From 4bb3aa5df3fac0a6a631b9f9e9229e98f5370f62 Mon Sep 17 00:00:00 2001
From: Camden Narzt <c.narzt@me.com>
Date: Mon, 9 Sep 2024 15:16:47 -0600
Subject: [PATCH 01/16] shut up clang about gcc pragmas

---
 src/agent/Core/ApplicationPool/Pool/StateInspection.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/agent/Core/ApplicationPool/Pool/StateInspection.cpp b/src/agent/Core/ApplicationPool/Pool/StateInspection.cpp
index f73f1d25ce..27b3fac326 100644
--- a/src/agent/Core/ApplicationPool/Pool/StateInspection.cpp
+++ b/src/agent/Core/ApplicationPool/Pool/StateInspection.cpp
@@ -81,12 +81,17 @@ Pool::inspectProcessList(const InspectOptions &options, stringstream &result,
 
 		 if (process->metrics.isValid()) {
 			snprintf(cpubuf, sizeof(cpubuf), "%d%%", (int) process->metrics.cpu);
+#ifndef __clang__
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wformat-truncation"
-			//don't worry about format-truncation here, no one has 9.3PB RAM
+#endif
+			// GCC warns about format-truncation here, but no one has 9.3PB RAM
+			// So we can safely ignore this warning.
 			snprintf(membuf, sizeof(membuf), "%ldM",
 				(unsigned long) (process->metrics.realMemory() / 1024));
+#ifndef __clang__
 #pragma GCC diagnostic pop
+#endif
 		} else {
 			snprintf(cpubuf, sizeof(cpubuf), "0%%");
 			snprintf(membuf, sizeof(membuf), "0M");

From 72eb3a88ded8a757e2284cbac31150fd704aaafd Mon Sep 17 00:00:00 2001
From: Camden Narzt <c.narzt@me.com>
Date: Mon, 9 Sep 2024 15:28:01 -0600
Subject: [PATCH 02/16] bump boost

---
 .../vendor-modified/boost/asio.hpp            |  15 +
 .../vendor-modified/boost/asio/as_tuple.hpp   |  44 +-
 .../asio/associated_immediate_executor.hpp    |   5 +-
 .../vendor-modified/boost/asio/associator.hpp |   2 +-
 .../boost/asio/async_result.hpp               | 142 ++--
 .../boost/asio/basic_datagram_socket.hpp      |  22 +-
 .../boost/asio/basic_deadline_timer.hpp       |   4 +-
 .../boost/asio/basic_random_access_file.hpp   |   4 +-
 .../boost/asio/basic_raw_socket.hpp           |  20 +-
 .../boost/asio/basic_readable_pipe.hpp        |   2 +-
 .../boost/asio/basic_seq_packet_socket.hpp    |   6 +-
 .../boost/asio/basic_serial_port.hpp          |   4 +-
 .../boost/asio/basic_signal_set.hpp           |   2 +-
 .../boost/asio/basic_socket.hpp               |   4 +-
 .../boost/asio/basic_socket_acceptor.hpp      |  18 +-
 .../boost/asio/basic_stream_file.hpp          |   4 +-
 .../boost/asio/basic_stream_socket.hpp        |  12 +-
 .../boost/asio/basic_waitable_timer.hpp       |   4 +-
 .../boost/asio/basic_writable_pipe.hpp        |   2 +-
 .../boost/asio/bind_allocator.hpp             | 110 ++-
 .../boost/asio/bind_cancellation_slot.hpp     | 113 ++-
 .../boost/asio/bind_executor.hpp              | 128 +++-
 .../boost/asio/bind_immediate_executor.hpp    | 113 ++-
 .../vendor-modified/boost/asio/buffer.hpp     |   4 +-
 .../boost/asio/buffer_registration.hpp        |   2 +-
 .../boost/asio/cancel_after.hpp               | 303 ++++++++
 .../vendor-modified/boost/asio/cancel_at.hpp  | 296 ++++++++
 .../{experimental/impl => }/co_composed.hpp   | 269 +++++--
 .../boost/asio/completion_condition.hpp       |  49 ++
 .../vendor-modified/boost/asio/compose.hpp    | 211 +-----
 .../vendor-modified/boost/asio/composed.hpp   | 415 ++++++++++
 .../vendor-modified/boost/asio/connect.hpp    | 262 +++++--
 .../vendor-modified/boost/asio/coroutine.hpp  |   7 +-
 .../boost/asio/default_completion_token.hpp   |  91 +++
 .../vendor-modified/boost/asio/deferred.hpp   |  14 +-
 .../vendor-modified/boost/asio/detached.hpp   |   4 +-
 .../asio/detail/buffered_stream_storage.hpp   |   2 +-
 .../completion_message.hpp}                   |  30 +-
 .../completion_payload.hpp}                   |  62 +-
 .../completion_payload_handler.hpp}           |  28 +-
 .../boost/asio/detail/config.hpp              |  58 +-
 .../asio/detail/deadline_timer_service.hpp    |   6 +-
 .../asio/detail/handler_alloc_helpers.hpp     | 132 +---
 .../boost/asio/detail/impl/descriptor_ops.ipp |  69 +-
 .../asio/detail/impl/dev_poll_reactor.ipp     |   2 +-
 .../impl/reactive_descriptor_service.ipp      |  12 +-
 .../impl/reactive_socket_service_base.ipp     |  10 +-
 .../boost/asio/detail/impl/socket_ops.ipp     |  79 +-
 .../detail/impl/socket_select_interrupter.ipp |   2 +-
 .../boost/asio/detail/initiation_base.hpp     |  64 ++
 .../boost/asio/detail/memory.hpp              |  11 -
 .../detail/reactive_descriptor_service.hpp    |  36 +-
 .../asio/detail/reactive_socket_send_op.hpp   |   1 -
 .../asio/detail/reactive_socket_service.hpp   |   8 +-
 .../detail/reactive_socket_service_base.hpp   |  41 +-
 .../boost/asio/detail/recycling_allocator.hpp |   9 +
 .../boost/asio/detail/resolve_endpoint_op.hpp |   2 +-
 .../boost/asio/detail/resolve_query_op.hpp    |   2 +-
 .../boost/asio/detail/thread_info_base.hpp    |  12 +-
 .../boost/asio/detail/timed_cancel_op.hpp     | 363 +++++++++
 .../boost/asio/detail/wrapped_handler.hpp     |  80 +-
 .../boost/asio/execution/allocator.hpp        |   2 +-
 .../boost/asio/execution/blocking.hpp         |   2 +-
 .../asio/execution/blocking_adaptation.hpp    |   2 +-
 .../boost/asio/execution/context.hpp          |   2 +-
 .../boost/asio/execution/mapping.hpp          |   2 +-
 .../boost/asio/execution/occupancy.hpp        |   2 +-
 .../boost/asio/execution/outstanding_work.hpp |   2 +-
 .../boost/asio/execution/relationship.hpp     |   2 +-
 .../boost/asio/experimental/basic_channel.hpp |   3 +-
 .../experimental/basic_concurrent_channel.hpp |   3 +-
 .../boost/asio/experimental/co_composed.hpp   | 116 +--
 .../detail/channel_receive_op.hpp             |   5 +-
 .../detail/channel_send_functions.hpp         |  46 +-
 .../experimental/detail/channel_send_op.hpp   |   1 -
 .../experimental/detail/channel_service.hpp   |  32 +-
 .../detail/coro_promise_allocator.hpp         |   5 +-
 .../detail/impl/channel_service.hpp           |   6 +-
 .../experimental/detail/partial_promise.hpp   |   8 +-
 .../asio/experimental/impl/as_single.hpp      |  19 +-
 .../boost/asio/experimental/impl/coro.hpp     |   2 +-
 .../asio/experimental/parallel_group.hpp      |  78 +-
 .../boost/asio/experimental/promise.hpp       |   6 +-
 .../boost/asio/experimental/use_coro.hpp      |  10 +-
 .../boost/asio/experimental/use_promise.hpp   |   2 +-
 .../vendor-modified/boost/asio/immediate.hpp  | 144 ++++
 .../boost/asio/impl/append.hpp                |  21 +-
 .../boost/asio/impl/as_tuple.hpp              |  59 +-
 .../boost/asio/impl/awaitable.hpp             |   6 +-
 .../boost/asio/impl/cancel_after.hpp          | 270 +++++++
 .../boost/asio/impl/cancel_at.hpp             | 270 +++++++
 .../boost/asio/impl/co_spawn.hpp              |   8 +
 .../boost/asio/impl/connect.hpp               | 226 ++----
 .../boost/asio/impl/consign.hpp               |  21 +-
 .../boost/asio/impl/detached.hpp              |   4 +-
 .../boost/asio/impl/prepend.hpp               |  21 +-
 .../vendor-modified/boost/asio/impl/read.hpp  | 203 +----
 .../boost/asio/impl/read_at.hpp               |  98 +--
 .../boost/asio/impl/read_until.hpp            | 299 +-------
 .../boost/asio/impl/redirect_error.hpp        |  73 +-
 .../vendor-modified/boost/asio/impl/spawn.hpp |   2 +-
 .../vendor-modified/boost/asio/impl/write.hpp | 211 +-----
 .../boost/asio/impl/write_at.hpp              | 103 +--
 .../boost/asio/io_context_strand.hpp          |  10 +-
 .../boost/asio/ip/basic_resolver.hpp          |  12 +-
 .../boost/asio/ip/detail/socket_option.hpp    |   2 +-
 .../boost/asio/ip/impl/address_v6.ipp         |   2 +-
 .../boost/asio/placeholders.hpp               |  18 +-
 .../boost/asio/posix/basic_descriptor.hpp     |   2 +-
 .../asio/posix/basic_stream_descriptor.hpp    |   4 +-
 .../vendor-modified/boost/asio/read.hpp       | 155 +++-
 .../vendor-modified/boost/asio/read_at.hpp    |  90 ++-
 .../vendor-modified/boost/asio/read_until.hpp | 150 +++-
 .../boost/asio/redirect_error.hpp             |  46 +-
 .../boost/asio/registered_buffer.hpp          |   4 +-
 .../vendor-modified/boost/asio/spawn.hpp      |   1 -
 .../asio/ssl/detail/impl/openssl_init.ipp     |   4 +-
 .../boost/asio/ssl/impl/context.ipp           |  17 +-
 .../vendor-modified/boost/asio/ssl/stream.hpp |  10 +-
 .../vendor-modified/boost/asio/this_coro.hpp  |   4 +-
 .../boost/asio/use_awaitable.hpp              |   4 +-
 .../vendor-modified/boost/asio/use_future.hpp |   2 +-
 .../boost/asio/uses_executor.hpp              |   2 +-
 .../vendor-modified/boost/asio/version.hpp    |   2 +-
 .../vendor-modified/boost/asio/write.hpp      | 182 ++++-
 .../vendor-modified/boost/asio/write_at.hpp   |  96 ++-
 .../boost/assert/source_location.hpp          |   5 +-
 .../boost/atomic/detail/futex.hpp             |  53 +-
 .../vendor-modified/boost/bind/bind.hpp       |  52 +-
 .../boost/container/adaptive_pool.hpp         |  16 +-
 .../boost/container/allocator.hpp             |   2 +-
 .../boost/container/allocator_traits.hpp      | 161 +++-
 .../boost/container/container_fwd.hpp         |  20 +-
 .../vendor-modified/boost/container/deque.hpp | 713 +++++++++++++++---
 .../container/detail/adaptive_node_pool.hpp   |   2 +-
 .../detail/adaptive_node_pool_impl.hpp        |  94 +--
 .../container/detail/advanced_insert_int.hpp  |  49 +-
 .../container/detail/allocation_type.hpp      |  14 +-
 .../boost/container/detail/block_list.hpp     |   4 +-
 .../boost/container/detail/block_slist.hpp    |   4 +-
 .../container/detail/construct_in_place.hpp   |  36 +-
 .../boost/container/detail/copy_move_algo.hpp |  28 +-
 .../detail/dispatch_uses_allocator.hpp        |   2 +-
 .../boost/container/detail/flat_tree.hpp      |  78 +-
 .../container/detail/function_detector.hpp    |   2 +-
 .../boost/container/detail/is_container.hpp   |   4 +-
 .../detail/is_contiguous_container.hpp        |   2 +-
 .../boost/container/detail/is_pair.hpp        |   8 +-
 .../boost/container/detail/iterators.hpp      |  16 +-
 .../boost/container/detail/math_functions.hpp |  18 +-
 .../boost/container/detail/mpl.hpp            |   8 +-
 .../detail/multiallocation_chain.hpp          | 106 ++-
 .../container/detail/node_alloc_holder.hpp    |  23 +-
 .../boost/container/detail/node_pool.hpp      |   2 +-
 .../boost/container/detail/pair.hpp           |  34 +-
 .../boost/container/detail/pool_common.hpp    |   2 +-
 .../container/detail/pool_common_alloc.hpp    |   4 +-
 .../boost/container/detail/pool_resource.hpp  |   8 +-
 .../boost/container/detail/tree.hpp           | 138 ++--
 .../boost/container/detail/version_type.hpp   |   8 +-
 .../boost/container/detail/workaround.hpp     |  12 +
 .../boost/container/devector.hpp              | 210 ++++--
 .../boost/container/flat_map.hpp              | 127 +++-
 .../boost/container/flat_set.hpp              |   4 +-
 .../vendor-modified/boost/container/list.hpp  |  52 +-
 .../vendor-modified/boost/container/map.hpp   |  21 +-
 .../boost/container/new_allocator.hpp         |   2 +-
 .../boost/container/node_allocator.hpp        |  23 +-
 .../boost/container/node_handle.hpp           |  11 +-
 .../boost/container/options.hpp               |  30 +-
 .../boost/container/pmr/memory_resource.hpp   |   2 +-
 .../pmr/monotonic_buffer_resource.hpp         |   2 +-
 .../boost/container/pmr/resource_adaptor.hpp  |   6 +-
 .../boost/container/scoped_allocator.hpp      |   2 +-
 .../vendor-modified/boost/container/set.hpp   |   4 +-
 .../vendor-modified/boost/container/slist.hpp |  55 +-
 .../boost/container/small_vector.hpp          |  88 +--
 .../boost/container/stable_vector.hpp         |  78 +-
 .../boost/container/static_vector.hpp         |  12 +-
 .../boost/container/string.hpp                | 102 +--
 .../boost/container/uses_allocator.hpp        |   6 +-
 .../boost/container/vector.hpp                | 295 ++++++--
 .../boost/core/detail/minstd_rand.hpp         |  58 ++
 .../boost/core/detail/string_view.hpp         |  26 +-
 .../boost/core/empty_value.hpp                |  58 +-
 .../boost/core/lightweight_test.hpp           |   1 +
 .../boost/core/pointer_in_range.hpp           |  49 ++
 .../vendor-modified/boost/core/span.hpp       |   2 +
 .../vendor-modified/boost/core/type_name.hpp  |   9 +-
 .../boost/function/function_base.hpp          |  56 +-
 .../boost/function/function_template.hpp      | 179 ++++-
 .../boost/intrusive/detail/algorithm.hpp      |  16 +-
 .../boost/intrusive/detail/hash.hpp           |   2 +-
 .../boost/intrusive/detail/hook_traits.hpp    |  14 +-
 .../boost/intrusive/pointer_traits.hpp        |  36 +-
 .../detail/converter_lexical_streams.hpp      |  39 +-
 .../boost/libs/random/src/random_device.cpp   |   4 +-
 .../boost/move/detail/config_begin.hpp        |   1 -
 .../boost/move/detail/launder.hpp             |  53 ++
 .../boost/move/detail/type_traits.hpp         |  10 +-
 .../boost/move/detail/workaround.hpp          |   7 +-
 .../vendor-modified/boost/mp11/version.hpp    |   2 +-
 .../boost/mpl/aux_/integral_wrapper.hpp       |   3 +-
 .../vendor-modified/boost/predef/version.h    |   2 +-
 .../boost/smart_ptr/detail/requires_cxx11.hpp |   2 +-
 .../detail/sp_has_gcc_intrinsics.hpp          |   5 +-
 .../detail/generic_category_message.hpp       |  14 +-
 .../boost/thread/detail/thread.hpp            |   4 +-
 .../boost/thread/exceptions.hpp               |   2 -
 .../vendor-modified/boost/thread/once.hpp     |   2 +-
 .../boost/unordered/concurrent_flat_map.hpp   |  14 +-
 .../unordered/concurrent_flat_map_fwd.hpp     |  15 +
 .../boost/unordered/concurrent_flat_set.hpp   |  14 +-
 .../unordered/concurrent_flat_set_fwd.hpp     |  15 +
 .../boost/unordered/detail/fca.hpp            |  28 +-
 .../unordered/detail/foa/concurrent_table.hpp |  48 +-
 .../boost/unordered/detail/foa/core.hpp       | 113 ++-
 .../unordered/detail/foa/cumulative_stats.hpp | 177 +++++
 .../boost/unordered/detail/foa/table.hpp      |  12 +-
 .../boost/unordered/hash_traits.hpp           |  40 +-
 .../boost/unordered/unordered_flat_map.hpp    |  12 +
 .../unordered/unordered_flat_map_fwd.hpp      |  15 +
 .../boost/unordered/unordered_flat_set.hpp    |  12 +
 .../unordered/unordered_flat_set_fwd.hpp      |  14 +
 .../boost/unordered/unordered_map_fwd.hpp     |  19 +
 .../boost/unordered/unordered_node_map.hpp    |  12 +
 .../unordered/unordered_node_map_fwd.hpp      |  15 +
 .../boost/unordered/unordered_node_set.hpp    |  12 +
 .../unordered/unordered_node_set_fwd.hpp      |  14 +
 .../boost/unordered/unordered_set_fwd.hpp     |  17 +
 .../boost/utility/detail/minstd_rand.hpp      |  44 +-
 .../vendor-modified/boost/version.hpp         |   4 +-
 232 files changed, 7786 insertions(+), 3440 deletions(-)
 create mode 100644 src/cxx_supportlib/vendor-modified/boost/asio/cancel_after.hpp
 create mode 100644 src/cxx_supportlib/vendor-modified/boost/asio/cancel_at.hpp
 rename src/cxx_supportlib/vendor-modified/boost/asio/{experimental/impl => }/co_composed.hpp (80%)
 create mode 100644 src/cxx_supportlib/vendor-modified/boost/asio/composed.hpp
 create mode 100644 src/cxx_supportlib/vendor-modified/boost/asio/default_completion_token.hpp
 rename src/cxx_supportlib/vendor-modified/boost/asio/{experimental/detail/channel_message.hpp => detail/completion_message.hpp} (79%)
 rename src/cxx_supportlib/vendor-modified/boost/asio/{experimental/detail/channel_payload.hpp => detail/completion_payload.hpp} (69%)
 rename src/cxx_supportlib/vendor-modified/boost/asio/{experimental/detail/channel_handler.hpp => detail/completion_payload_handler.hpp} (69%)
 create mode 100644 src/cxx_supportlib/vendor-modified/boost/asio/detail/initiation_base.hpp
 create mode 100644 src/cxx_supportlib/vendor-modified/boost/asio/detail/timed_cancel_op.hpp
 create mode 100644 src/cxx_supportlib/vendor-modified/boost/asio/immediate.hpp
 create mode 100644 src/cxx_supportlib/vendor-modified/boost/asio/impl/cancel_after.hpp
 create mode 100644 src/cxx_supportlib/vendor-modified/boost/asio/impl/cancel_at.hpp
 create mode 100644 src/cxx_supportlib/vendor-modified/boost/core/detail/minstd_rand.hpp
 create mode 100644 src/cxx_supportlib/vendor-modified/boost/core/pointer_in_range.hpp
 create mode 100644 src/cxx_supportlib/vendor-modified/boost/move/detail/launder.hpp
 create mode 100644 src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/cumulative_stats.hpp

diff --git a/src/cxx_supportlib/vendor-modified/boost/asio.hpp b/src/cxx_supportlib/vendor-modified/boost/asio.hpp
index 1d526b8ae8..09efee9d6a 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio.hpp
@@ -61,12 +61,16 @@
 #include <boost/asio/buffered_write_stream_fwd.hpp>
 #include <boost/asio/buffered_write_stream.hpp>
 #include <boost/asio/buffers_iterator.hpp>
+#include <boost/asio/cancel_after.hpp>
+#include <boost/asio/cancel_at.hpp>
 #include <boost/asio/cancellation_signal.hpp>
 #include <boost/asio/cancellation_state.hpp>
 #include <boost/asio/cancellation_type.hpp>
+#include <boost/asio/co_composed.hpp>
 #include <boost/asio/co_spawn.hpp>
 #include <boost/asio/completion_condition.hpp>
 #include <boost/asio/compose.hpp>
+#include <boost/asio/composed.hpp>
 #include <boost/asio/connect.hpp>
 #include <boost/asio/connect_pipe.hpp>
 #include <boost/asio/consign.hpp>
@@ -74,6 +78,7 @@
 #include <boost/asio/deadline_timer.hpp>
 #include <boost/asio/defer.hpp>
 #include <boost/asio/deferred.hpp>
+#include <boost/asio/default_completion_token.hpp>
 #include <boost/asio/detached.hpp>
 #include <boost/asio/dispatch.hpp>
 #include <boost/asio/error.hpp>
@@ -101,6 +106,7 @@
 #include <boost/asio/generic/stream_protocol.hpp>
 #include <boost/asio/handler_continuation_hook.hpp>
 #include <boost/asio/high_resolution_timer.hpp>
+#include <boost/asio/immediate.hpp>
 #include <boost/asio/io_context.hpp>
 #include <boost/asio/io_context_strand.hpp>
 #include <boost/asio/io_service.hpp>
@@ -182,6 +188,15 @@
 #include <boost/asio/uses_executor.hpp>
 #include <boost/asio/version.hpp>
 #include <boost/asio/wait_traits.hpp>
+#include <boost/asio/windows/basic_object_handle.hpp>
+#include <boost/asio/windows/basic_overlapped_handle.hpp>
+#include <boost/asio/windows/basic_random_access_handle.hpp>
+#include <boost/asio/windows/basic_stream_handle.hpp>
+#include <boost/asio/windows/object_handle.hpp>
+#include <boost/asio/windows/overlapped_handle.hpp>
+#include <boost/asio/windows/overlapped_ptr.hpp>
+#include <boost/asio/windows/random_access_handle.hpp>
+#include <boost/asio/windows/stream_handle.hpp>
 #include <boost/asio/writable_pipe.hpp>
 #include <boost/asio/write.hpp>
 #include <boost/asio/write_at.hpp>
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/as_tuple.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/as_tuple.hpp
index 6e91d8edd5..be508b8681 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/as_tuple.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/as_tuple.hpp
@@ -107,16 +107,42 @@ class as_tuple_t
   CompletionToken token_;
 };
 
-/// Adapt a @ref completion_token to specify that the completion handler
-/// arguments should be combined into a single tuple argument.
-template <typename CompletionToken>
-BOOST_ASIO_NODISCARD inline
-constexpr as_tuple_t<decay_t<CompletionToken>>
-as_tuple(CompletionToken&& completion_token)
+/// A function object type that adapts a @ref completion_token to specify that
+/// the completion handler arguments should be combined into a single tuple
+/// argument.
+/**
+ * May also be used directly as a completion token, in which case it adapts the
+ * asynchronous operation's default completion token (or boost::asio::deferred
+ * if no default is available).
+ */
+struct partial_as_tuple
 {
-  return as_tuple_t<decay_t<CompletionToken>>(
-      static_cast<CompletionToken&&>(completion_token));
-}
+  /// Default constructor.
+  constexpr partial_as_tuple()
+  {
+  }
+
+  /// Adapt a @ref completion_token to specify that the completion handler
+  /// arguments should be combined into a single tuple argument.
+  template <typename CompletionToken>
+  BOOST_ASIO_NODISCARD inline
+  constexpr as_tuple_t<decay_t<CompletionToken>>
+  operator()(CompletionToken&& completion_token) const
+  {
+    return as_tuple_t<decay_t<CompletionToken>>(
+        static_cast<CompletionToken&&>(completion_token));
+  }
+};
+
+/// A function object that adapts a @ref completion_token to specify that the
+/// completion handler arguments should be combined into a single tuple
+/// argument.
+/**
+ * May also be used directly as a completion token, in which case it adapts the
+ * asynchronous operation's default completion token (or boost::asio::deferred
+ * if no default is available).
+ */
+BOOST_ASIO_INLINE_VARIABLE constexpr partial_as_tuple as_tuple;
 
 } // namespace asio
 } // namespace boost
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/associated_immediate_executor.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/associated_immediate_executor.hpp
index 7e898f478f..64fa4d943d 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/associated_immediate_executor.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/associated_immediate_executor.hpp
@@ -50,9 +50,10 @@ struct has_immediate_executor_type<T,
 template <typename E, typename = void, typename = void>
 struct default_immediate_executor
 {
-  typedef require_result_t<E, execution::blocking_t::never_t> type;
+  typedef decay_t<require_result_t<E, execution::blocking_t::never_t>> type;
 
-  static type get(const E& e) noexcept
+  static auto get(const E& e) noexcept
+    -> decltype(boost::asio::require(e, execution::blocking.never))
   {
     return boost::asio::require(e, execution::blocking.never);
   }
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/associator.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/associator.hpp
index 3096de3e2c..d9f5e6e94e 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/associator.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/associator.hpp
@@ -24,7 +24,7 @@ namespace asio {
 
 /// Used to generically specialise associators for a type.
 template <template <typename, typename> class Associator,
-    typename T, typename DefaultCandidate>
+    typename T, typename DefaultCandidate, typename _ = void>
 struct associator
 {
 };
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/async_result.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/async_result.hpp
index 63d2169a56..894a94d231 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/async_result.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/async_result.hpp
@@ -22,9 +22,6 @@
 
 namespace boost {
 namespace asio {
-
-#if defined(BOOST_ASIO_HAS_CONCEPTS)
-
 namespace detail {
 
 template <typename T>
@@ -71,6 +68,12 @@ struct are_completion_signatures : false_type
 {
 };
 
+template <>
+struct are_completion_signatures<>
+  : true_type
+{
+};
+
 template <typename T0>
 struct are_completion_signatures<T0>
   : is_completion_signature<T0>
@@ -85,6 +88,12 @@ struct are_completion_signatures<T0, TN...>
 {
 };
 
+} // namespace detail
+
+#if defined(BOOST_ASIO_HAS_CONCEPTS)
+
+namespace detail {
+
 template <typename T, typename... Args>
 BOOST_ASIO_CONCEPT callable_with = requires(T&& t, Args&&... args)
 {
@@ -607,14 +616,36 @@ template <typename CompletionToken,
     typename Initiation, typename... Args>
 inline auto async_initiate(Initiation&& initiation,
     type_identity_t<CompletionToken>& token, Args&&... args)
-  -> constraint_t<
-    detail::async_result_has_initiate_memfn<
-      CompletionToken, Signatures...>::value,
-    decltype(
-      async_result<decay_t<CompletionToken>, Signatures...>::initiate(
-        static_cast<Initiation&&>(initiation),
-        static_cast<CompletionToken&&>(token),
-        static_cast<Args&&>(args)...))>
+  -> decltype(enable_if_t<
+    enable_if_t<
+      detail::are_completion_signatures<Signatures...>::value,
+      detail::async_result_has_initiate_memfn<
+        CompletionToken, Signatures...>>::value,
+    async_result<decay_t<CompletionToken>, Signatures...>>::initiate(
+      static_cast<Initiation&&>(initiation),
+      static_cast<CompletionToken&&>(token),
+      static_cast<Args&&>(args)...))
+{
+  return async_result<decay_t<CompletionToken>, Signatures...>::initiate(
+      static_cast<Initiation&&>(initiation),
+      static_cast<CompletionToken&&>(token),
+      static_cast<Args&&>(args)...);
+}
+
+template <
+    BOOST_ASIO_COMPLETION_SIGNATURE... Signatures,
+    typename CompletionToken, typename Initiation, typename... Args>
+inline auto async_initiate(Initiation&& initiation,
+    CompletionToken&& token, Args&&... args)
+  -> decltype(enable_if_t<
+    enable_if_t<
+      detail::are_completion_signatures<Signatures...>::value,
+      detail::async_result_has_initiate_memfn<
+        CompletionToken, Signatures...>>::value,
+    async_result<decay_t<CompletionToken>, Signatures...>>::initiate(
+      static_cast<Initiation&&>(initiation),
+      static_cast<CompletionToken&&>(token),
+      static_cast<Args&&>(args)...))
 {
   return async_result<decay_t<CompletionToken>, Signatures...>::initiate(
       static_cast<Initiation&&>(initiation),
@@ -625,10 +656,13 @@ inline auto async_initiate(Initiation&& initiation,
 template <typename CompletionToken,
     BOOST_ASIO_COMPLETION_SIGNATURE... Signatures,
     typename Initiation, typename... Args>
-inline constraint_t<
-    !detail::async_result_has_initiate_memfn<
-      CompletionToken, Signatures...>::value,
-    typename async_result<decay_t<CompletionToken>, Signatures...>::return_type>
+inline typename enable_if_t<
+    !enable_if_t<
+      detail::are_completion_signatures<Signatures...>::value,
+      detail::async_result_has_initiate_memfn<
+        CompletionToken, Signatures...>>::value,
+    async_result<decay_t<CompletionToken>, Signatures...>
+  >::return_type
 async_initiate(Initiation&& initiation,
     type_identity_t<CompletionToken>& token, Args&&... args)
 {
@@ -644,6 +678,29 @@ async_initiate(Initiation&& initiation,
   return completion.result.get();
 }
 
+template <BOOST_ASIO_COMPLETION_SIGNATURE... Signatures,
+    typename CompletionToken, typename Initiation, typename... Args>
+inline typename enable_if_t<
+    !enable_if_t<
+      detail::are_completion_signatures<Signatures...>::value,
+      detail::async_result_has_initiate_memfn<
+        CompletionToken, Signatures...>>::value,
+    async_result<decay_t<CompletionToken>, Signatures...>
+  >::return_type
+async_initiate(Initiation&& initiation, CompletionToken&& token, Args&&... args)
+{
+  async_completion<CompletionToken, Signatures...> completion(token);
+
+  static_cast<Initiation&&>(initiation)(
+      static_cast<
+        typename async_result<decay_t<CompletionToken>,
+          Signatures...>::completion_handler_type&&>(
+            completion.completion_handler),
+      static_cast<Args&&>(args)...);
+
+  return completion.result.get();
+}
+
 #endif // defined(GENERATING_DOCUMENTATION)
 
 #if defined(BOOST_ASIO_HAS_CONCEPTS)
@@ -883,62 +940,11 @@ template <typename T, typename... Args>
 using completion_signature_of_t =
   typename completion_signature_of<T, Args...>::type;
 
-namespace detail {
-
-template <typename T, typename = void>
-struct default_completion_token_impl
-{
-  typedef void type;
-};
-
-template <typename T>
-struct default_completion_token_impl<T,
-    void_t<typename T::default_completion_token_type>
-  >
-{
-  typedef typename T::default_completion_token_type type;
-};
-
-} // namespace detail
-
-#if defined(GENERATING_DOCUMENTATION)
-
-/// Traits type used to determine the default completion token type associated
-/// with a type (such as an executor).
-/**
- * A program may specialise this traits type if the @c T template parameter in
- * the specialisation is a user-defined type.
- *
- * Specialisations of this trait may provide a nested typedef @c type, which is
- * a default-constructible completion token type.
- */
-template <typename T>
-struct default_completion_token
-{
-  /// If @c T has a nested type @c default_completion_token_type,
-  /// <tt>T::default_completion_token_type</tt>. Otherwise the typedef @c type
-  /// is not defined.
-  typedef see_below type;
-};
-#else
-template <typename T>
-struct default_completion_token
-  : detail::default_completion_token_impl<T>
-{
-};
-#endif
-
-template <typename T>
-using default_completion_token_t = typename default_completion_token<T>::type;
-
-#define BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(e) \
-  = typename ::boost::asio::default_completion_token<e>::type
-#define BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(e) \
-  = typename ::boost::asio::default_completion_token<e>::type()
-
 } // namespace asio
 } // namespace boost
 
 #include <boost/asio/detail/pop_options.hpp>
 
+#include <boost/asio/default_completion_token.hpp>
+
 #endif // BOOST_ASIO_ASYNC_RESULT_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/basic_datagram_socket.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/basic_datagram_socket.hpp
index ecf1abb848..88738d939c 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/basic_datagram_socket.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/basic_datagram_socket.hpp
@@ -448,7 +448,7 @@ class basic_datagram_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -518,7 +518,7 @@ class basic_datagram_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -667,7 +667,7 @@ class basic_datagram_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -740,7 +740,7 @@ class basic_datagram_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -885,7 +885,7 @@ class basic_datagram_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -956,7 +956,7 @@ class basic_datagram_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1027,7 +1027,7 @@ class basic_datagram_socket
     boost::asio::detail::throw_error(ec, "receive_from");
     return s;
   }
-  
+
   /// Receive a datagram with the endpoint of the sender.
   /**
    * This function is used to receive a datagram. The function call will block
@@ -1054,7 +1054,7 @@ class basic_datagram_socket
     boost::asio::detail::throw_error(ec, "receive_from");
     return s;
   }
-  
+
   /// Receive a datagram with the endpoint of the sender.
   /**
    * This function is used to receive a datagram. The function call will block
@@ -1108,7 +1108,7 @@ class basic_datagram_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1180,7 +1180,7 @@ class basic_datagram_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1220,7 +1220,7 @@ class basic_datagram_socket
       const basic_datagram_socket&) = delete;
 
   class initiate_async_send
-  { 
+  {
   public:
     typedef Executor executor_type;
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/basic_deadline_timer.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/basic_deadline_timer.hpp
index 3d68f4528f..742d6cb8fa 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/basic_deadline_timer.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/basic_deadline_timer.hpp
@@ -64,7 +64,7 @@ namespace asio {
  * timer.wait();
  * @endcode
  *
- * @par 
+ * @par
  * Performing an asynchronous wait:
  * @code
  * void handler(const boost::system::error_code& error)
@@ -631,7 +631,7 @@ class basic_deadline_timer
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code) @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/basic_random_access_file.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/basic_random_access_file.hpp
index f9e109bb52..099514f689 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/basic_random_access_file.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/basic_random_access_file.hpp
@@ -428,7 +428,7 @@ class basic_random_access_file
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -563,7 +563,7 @@ class basic_random_access_file
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/basic_raw_socket.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/basic_raw_socket.hpp
index f9c64d5d46..97dfd95f4b 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/basic_raw_socket.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/basic_raw_socket.hpp
@@ -440,7 +440,7 @@ class basic_raw_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -510,7 +510,7 @@ class basic_raw_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -659,7 +659,7 @@ class basic_raw_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -732,7 +732,7 @@ class basic_raw_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -877,7 +877,7 @@ class basic_raw_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -948,7 +948,7 @@ class basic_raw_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1020,7 +1020,7 @@ class basic_raw_socket
     boost::asio::detail::throw_error(ec, "receive_from");
     return s;
   }
-  
+
   /// Receive raw data with the endpoint of the sender.
   /**
    * This function is used to receive raw data. The function call will block
@@ -1047,7 +1047,7 @@ class basic_raw_socket
     boost::asio::detail::throw_error(ec, "receive_from");
     return s;
   }
-  
+
   /// Receive raw data with the endpoint of the sender.
   /**
    * This function is used to receive raw data. The function call will block
@@ -1101,7 +1101,7 @@ class basic_raw_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1174,7 +1174,7 @@ class basic_raw_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/basic_readable_pipe.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/basic_readable_pipe.hpp
index 9917823ec3..2e88cad8e7 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/basic_readable_pipe.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/basic_readable_pipe.hpp
@@ -535,7 +535,7 @@ class basic_readable_pipe
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/basic_seq_packet_socket.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/basic_seq_packet_socket.hpp
index cf822cfde1..7928d881ff 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/basic_seq_packet_socket.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/basic_seq_packet_socket.hpp
@@ -431,7 +431,7 @@ class basic_seq_packet_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -621,7 +621,7 @@ class basic_seq_packet_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -695,7 +695,7 @@ class basic_seq_packet_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/basic_serial_port.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/basic_serial_port.hpp
index c4cb0a3f05..fdfc01bfe9 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/basic_serial_port.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/basic_serial_port.hpp
@@ -725,7 +725,7 @@ class basic_serial_port
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -855,7 +855,7 @@ class basic_serial_port
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/basic_signal_set.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/basic_signal_set.hpp
index e4cde56419..fb3b22d2e1 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/basic_signal_set.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/basic_signal_set.hpp
@@ -574,7 +574,7 @@ class basic_signal_set : public signal_set_base
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, int) @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/basic_socket.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/basic_socket.hpp
index 6eb4290c53..aacce47a78 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/basic_socket.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/basic_socket.hpp
@@ -928,7 +928,7 @@ class basic_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code) @endcode
@@ -1780,7 +1780,7 @@ class basic_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code) @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/basic_socket_acceptor.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/basic_socket_acceptor.hpp
index cefc362372..a2254a43e9 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/basic_socket_acceptor.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/basic_socket_acceptor.hpp
@@ -1214,7 +1214,7 @@ class basic_socket_acceptor
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code) @endcode
@@ -1349,7 +1349,7 @@ class basic_socket_acceptor
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code) @endcode
@@ -1497,7 +1497,7 @@ class basic_socket_acceptor
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code) @endcode
@@ -1617,7 +1617,7 @@ class basic_socket_acceptor
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code,
@@ -1867,7 +1867,7 @@ class basic_socket_acceptor
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code,
@@ -1963,7 +1963,7 @@ class basic_socket_acceptor
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code,
@@ -2133,7 +2133,7 @@ class basic_socket_acceptor
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code,
@@ -2415,7 +2415,7 @@ class basic_socket_acceptor
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code,
@@ -2515,7 +2515,7 @@ class basic_socket_acceptor
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code,
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/basic_stream_file.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/basic_stream_file.hpp
index 314506f71c..b99fa9b60b 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/basic_stream_file.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/basic_stream_file.hpp
@@ -491,7 +491,7 @@ class basic_stream_file
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -619,7 +619,7 @@ class basic_stream_file
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/basic_stream_socket.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/basic_stream_socket.hpp
index 55a6ccafe2..77896a48ae 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/basic_stream_socket.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/basic_stream_socket.hpp
@@ -462,7 +462,7 @@ class basic_stream_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -532,7 +532,7 @@ class basic_stream_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -704,7 +704,7 @@ class basic_stream_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -776,7 +776,7 @@ class basic_stream_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -906,7 +906,7 @@ class basic_stream_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1037,7 +1037,7 @@ class basic_stream_socket
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/basic_waitable_timer.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/basic_waitable_timer.hpp
index eb8967e42d..484b311862 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/basic_waitable_timer.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/basic_waitable_timer.hpp
@@ -76,7 +76,7 @@ class basic_waitable_timer;
  * timer.wait();
  * @endcode
  *
- * @par 
+ * @par
  * Performing an asynchronous wait (C++11):
  * @code
  * void handler(const boost::system::error_code& error)
@@ -747,7 +747,7 @@ class basic_waitable_timer
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code) @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/basic_writable_pipe.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/basic_writable_pipe.hpp
index 2e7536cd04..9aa58525f2 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/basic_writable_pipe.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/basic_writable_pipe.hpp
@@ -533,7 +533,7 @@ class basic_writable_pipe
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/bind_allocator.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/bind_allocator.hpp
index 9a7134adce..ac7faaf8c6 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/bind_allocator.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/bind_allocator.hpp
@@ -16,10 +16,12 @@
 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
 
 #include <boost/asio/detail/config.hpp>
-#include <boost/asio/detail/type_traits.hpp>
 #include <boost/asio/associated_allocator.hpp>
+#include <boost/asio/associated_executor.hpp>
 #include <boost/asio/associator.hpp>
 #include <boost/asio/async_result.hpp>
+#include <boost/asio/detail/initiation_base.hpp>
+#include <boost/asio/detail/type_traits.hpp>
 
 #include <boost/asio/detail/push_options.hpp>
 
@@ -361,6 +363,46 @@ class allocator_binder
   T target_;
 };
 
+/// A function object type that adapts a @ref completion_token to specify that
+/// the completion handler should have the supplied allocator as its associated
+/// allocator.
+/**
+ * May also be used directly as a completion token, in which case it adapts the
+ * asynchronous operation's default completion token (or boost::asio::deferred
+ * if no default is available).
+ */
+template <typename Allocator>
+struct partial_allocator_binder
+{
+  /// Constructor that specifies associated allocator.
+  explicit partial_allocator_binder(const Allocator& ex)
+    : allocator_(ex)
+  {
+  }
+
+  /// Adapt a @ref completion_token to specify that the completion handler
+  /// should have the allocator as its associated allocator.
+  template <typename CompletionToken>
+  BOOST_ASIO_NODISCARD inline
+  constexpr allocator_binder<decay_t<CompletionToken>, Allocator>
+  operator()(CompletionToken&& completion_token) const
+  {
+    return allocator_binder<decay_t<CompletionToken>, Allocator>(
+        allocator_, static_cast<CompletionToken&&>(completion_token));
+  }
+
+//private:
+  Allocator allocator_;
+};
+
+/// Create a partial completion token that associates an allocator.
+template <typename Allocator>
+BOOST_ASIO_NODISCARD inline partial_allocator_binder<Allocator>
+bind_allocator(const Allocator& ex)
+{
+  return partial_allocator_binder<Allocator>(ex);
+}
+
 /// Associate an object of type @c T with an allocator of type
 /// @c Allocator.
 template <typename Allocator, typename T>
@@ -438,49 +480,48 @@ class async_result<allocator_binder<T, Allocator>, Signature> :
   }
 
   template <typename Initiation>
-  struct init_wrapper
+  struct init_wrapper : detail::initiation_base<Initiation>
   {
-    template <typename Init>
-    init_wrapper(const Allocator& allocator, Init&& init)
-      : allocator_(allocator),
-        initiation_(static_cast<Init&&>(init))
-    {
-    }
+    using detail::initiation_base<Initiation>::initiation_base;
 
     template <typename Handler, typename... Args>
-    void operator()(Handler&& handler, Args&&... args)
+    void operator()(Handler&& handler, const Allocator& a, Args&&... args) &&
     {
-      static_cast<Initiation&&>(initiation_)(
+      static_cast<Initiation&&>(*this)(
           allocator_binder<decay_t<Handler>, Allocator>(
-              allocator_, static_cast<Handler&&>(handler)),
+              a, static_cast<Handler&&>(handler)),
           static_cast<Args&&>(args)...);
     }
 
     template <typename Handler, typename... Args>
-    void operator()(Handler&& handler, Args&&... args) const
+    void operator()(Handler&& handler,
+        const Allocator& a, Args&&... args) const &
     {
-      initiation_(
+      static_cast<const Initiation&>(*this)(
           allocator_binder<decay_t<Handler>, Allocator>(
-              allocator_, static_cast<Handler&&>(handler)),
+              a, static_cast<Handler&&>(handler)),
           static_cast<Args&&>(args)...);
     }
-
-    Allocator allocator_;
-    Initiation initiation_;
   };
 
   template <typename Initiation, typename RawCompletionToken, typename... Args>
   static auto initiate(Initiation&& initiation,
       RawCompletionToken&& token, Args&&... args)
     -> decltype(
-      async_initiate<T, Signature>(
+      async_initiate<
+        conditional_t<
+          is_const<remove_reference_t<RawCompletionToken>>::value, const T, T>,
+        Signature>(
         declval<init_wrapper<decay_t<Initiation>>>(),
-        token.get(), static_cast<Args&&>(args)...))
+        token.get(), token.get_allocator(), static_cast<Args&&>(args)...))
   {
-    return async_initiate<T, Signature>(
-        init_wrapper<decay_t<Initiation>>(token.get_allocator(),
+    return async_initiate<
+      conditional_t<
+        is_const<remove_reference_t<RawCompletionToken>>::value, const T, T>,
+      Signature>(
+        init_wrapper<decay_t<Initiation>>(
           static_cast<Initiation&&>(initiation)),
-        token.get(), static_cast<Args&&>(args)...);
+        token.get(), token.get_allocator(), static_cast<Args&&>(args)...);
   }
 
 private:
@@ -490,6 +531,31 @@ class async_result<allocator_binder<T, Allocator>, Signature> :
   async_result<T, Signature> target_;
 };
 
+template <typename Allocator, typename... Signatures>
+struct async_result<partial_allocator_binder<Allocator>, Signatures...>
+{
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static auto initiate(Initiation&& initiation,
+      RawCompletionToken&& token, Args&&... args)
+    -> decltype(
+      async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        allocator_binder<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          Allocator>(token.allocator_,
+            default_completion_token_t<associated_executor_t<Initiation>>{}),
+        static_cast<Args&&>(args)...))
+  {
+    return async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        allocator_binder<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          Allocator>(token.allocator_,
+            default_completion_token_t<associated_executor_t<Initiation>>{}),
+        static_cast<Args&&>(args)...);
+  }
+};
+
 template <template <typename, typename> class Associator,
     typename T, typename Allocator, typename DefaultCandidate>
 struct associator<Associator, allocator_binder<T, Allocator>, DefaultCandidate>
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/bind_cancellation_slot.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/bind_cancellation_slot.hpp
index acf724b9eb..38e8571fbe 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/bind_cancellation_slot.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/bind_cancellation_slot.hpp
@@ -16,10 +16,12 @@
 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
 
 #include <boost/asio/detail/config.hpp>
-#include <boost/asio/detail/type_traits.hpp>
 #include <boost/asio/associated_cancellation_slot.hpp>
+#include <boost/asio/associated_executor.hpp>
 #include <boost/asio/associator.hpp>
 #include <boost/asio/async_result.hpp>
+#include <boost/asio/detail/initiation_base.hpp>
+#include <boost/asio/detail/type_traits.hpp>
 
 #include <boost/asio/detail/push_options.hpp>
 
@@ -367,6 +369,46 @@ class cancellation_slot_binder
   T target_;
 };
 
+/// A function object type that adapts a @ref completion_token to specify that
+/// the completion handler should have the supplied cancellation slot as its
+/// associated cancellation slot.
+/**
+ * May also be used directly as a completion token, in which case it adapts the
+ * asynchronous operation's default completion token (or boost::asio::deferred
+ * if no default is available).
+ */
+template <typename CancellationSlot>
+struct partial_cancellation_slot_binder
+{
+  /// Constructor that specifies associated cancellation slot.
+  explicit partial_cancellation_slot_binder(const CancellationSlot& ex)
+    : cancellation_slot_(ex)
+  {
+  }
+
+  /// Adapt a @ref completion_token to specify that the completion handler
+  /// should have the cancellation slot as its associated cancellation slot.
+  template <typename CompletionToken>
+  BOOST_ASIO_NODISCARD inline
+  constexpr cancellation_slot_binder<decay_t<CompletionToken>, CancellationSlot>
+  operator()(CompletionToken&& completion_token) const
+  {
+    return cancellation_slot_binder<decay_t<CompletionToken>, CancellationSlot>(
+        static_cast<CompletionToken&&>(completion_token), cancellation_slot_);
+  }
+
+//private:
+  CancellationSlot cancellation_slot_;
+};
+
+/// Create a partial completion token that associates a cancellation slot.
+template <typename CancellationSlot>
+BOOST_ASIO_NODISCARD inline partial_cancellation_slot_binder<CancellationSlot>
+bind_cancellation_slot(const CancellationSlot& ex)
+{
+  return partial_cancellation_slot_binder<CancellationSlot>(ex);
+}
+
 /// Associate an object of type @c T with a cancellation slot of type
 /// @c CancellationSlot.
 template <typename CancellationSlot, typename T>
@@ -447,50 +489,51 @@ class async_result<cancellation_slot_binder<T, CancellationSlot>, Signature> :
   }
 
   template <typename Initiation>
-  struct init_wrapper
+  struct init_wrapper : detail::initiation_base<Initiation>
   {
-    template <typename Init>
-    init_wrapper(const CancellationSlot& slot, Init&& init)
-      : slot_(slot),
-        initiation_(static_cast<Init&&>(init))
-    {
-    }
+    using detail::initiation_base<Initiation>::initiation_base;
 
     template <typename Handler, typename... Args>
-    void operator()(Handler&& handler, Args&&... args)
+    void operator()(Handler&& handler,
+        const CancellationSlot& slot, Args&&... args) &&
     {
-      static_cast<Initiation&&>(initiation_)(
+      static_cast<Initiation&&>(*this)(
           cancellation_slot_binder<decay_t<Handler>, CancellationSlot>(
-              slot_, static_cast<Handler&&>(handler)),
+              slot, static_cast<Handler&&>(handler)),
           static_cast<Args&&>(args)...);
     }
 
     template <typename Handler, typename... Args>
-    void operator()(Handler&& handler, Args&&... args) const
+    void operator()(Handler&& handler,
+        const CancellationSlot& slot, Args&&... args) const &
     {
-      initiation_(
+      static_cast<const Initiation&>(*this)(
           cancellation_slot_binder<decay_t<Handler>, CancellationSlot>(
-              slot_, static_cast<Handler&&>(handler)),
+              slot, static_cast<Handler&&>(handler)),
           static_cast<Args&&>(args)...);
     }
-
-    CancellationSlot slot_;
-    Initiation initiation_;
   };
 
   template <typename Initiation, typename RawCompletionToken, typename... Args>
   static auto initiate(Initiation&& initiation,
       RawCompletionToken&& token, Args&&... args)
     -> decltype(
-      async_initiate<T, Signature>(
+      async_initiate<
+        conditional_t<
+          is_const<remove_reference_t<RawCompletionToken>>::value, const T, T>,
+        Signature>(
         declval<init_wrapper<decay_t<Initiation>>>(),
-        token.get(), static_cast<Args&&>(args)...))
+        token.get(), token.get_cancellation_slot(),
+        static_cast<Args&&>(args)...))
   {
-    return async_initiate<T, Signature>(
+    return async_initiate<
+      conditional_t<
+        is_const<remove_reference_t<RawCompletionToken>>::value, const T, T>,
+      Signature>(
         init_wrapper<decay_t<Initiation>>(
-          token.get_cancellation_slot(),
           static_cast<Initiation&&>(initiation)),
-        token.get(), static_cast<Args&&>(args)...);
+        token.get(), token.get_cancellation_slot(),
+        static_cast<Args&&>(args)...);
   }
 
 private:
@@ -500,6 +543,32 @@ class async_result<cancellation_slot_binder<T, CancellationSlot>, Signature> :
   async_result<T, Signature> target_;
 };
 
+template <typename CancellationSlot, typename... Signatures>
+struct async_result<partial_cancellation_slot_binder<CancellationSlot>,
+    Signatures...>
+{
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static auto initiate(Initiation&& initiation,
+      RawCompletionToken&& token, Args&&... args)
+    -> decltype(
+      async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        cancellation_slot_binder<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          CancellationSlot>(token.cancellation_slot_,
+            default_completion_token_t<associated_executor_t<Initiation>>{}),
+        static_cast<Args&&>(args)...))
+  {
+    return async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        cancellation_slot_binder<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          CancellationSlot>(token.cancellation_slot_,
+            default_completion_token_t<associated_executor_t<Initiation>>{}),
+        static_cast<Args&&>(args)...);
+  }
+};
+
 template <template <typename, typename> class Associator,
     typename T, typename CancellationSlot, typename DefaultCandidate>
 struct associator<Associator,
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/bind_executor.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/bind_executor.hpp
index b38d2c8933..818b32e4b0 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/bind_executor.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/bind_executor.hpp
@@ -16,10 +16,11 @@
 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
 
 #include <boost/asio/detail/config.hpp>
-#include <boost/asio/detail/type_traits.hpp>
 #include <boost/asio/associated_executor.hpp>
 #include <boost/asio/associator.hpp>
 #include <boost/asio/async_result.hpp>
+#include <boost/asio/detail/initiation_base.hpp>
+#include <boost/asio/detail/type_traits.hpp>
 #include <boost/asio/execution/executor.hpp>
 #include <boost/asio/execution_context.hpp>
 #include <boost/asio/is_executor.hpp>
@@ -395,6 +396,49 @@ class executor_binder
     uses_executor<T, Executor>::value> base_type;
 };
 
+/// A function object type that adapts a @ref completion_token to specify that
+/// the completion handler should have the supplied executor as its associated
+/// executor.
+/**
+ * May also be used directly as a completion token, in which case it adapts the
+ * asynchronous operation's default completion token (or boost::asio::deferred
+ * if no default is available).
+ */
+template <typename Executor>
+struct partial_executor_binder
+{
+  /// Constructor that specifies associated executor.
+  explicit partial_executor_binder(const Executor& ex)
+    : executor_(ex)
+  {
+  }
+
+  /// Adapt a @ref completion_token to specify that the completion handler
+  /// should have the executor as its associated executor.
+  template <typename CompletionToken>
+  BOOST_ASIO_NODISCARD inline
+  constexpr executor_binder<decay_t<CompletionToken>, Executor>
+  operator()(CompletionToken&& completion_token) const
+  {
+    return executor_binder<decay_t<CompletionToken>, Executor>(executor_arg_t(),
+        static_cast<CompletionToken&&>(completion_token), executor_);
+  }
+
+//private:
+  Executor executor_;
+};
+
+/// Create a partial completion token that associates an executor.
+template <typename Executor>
+BOOST_ASIO_NODISCARD inline partial_executor_binder<Executor>
+bind_executor(const Executor& ex,
+    constraint_t<
+      is_executor<Executor>::value || execution::is_executor<Executor>::value
+    > = 0)
+{
+  return partial_executor_binder<Executor>(ex);
+}
+
 /// Associate an object of type @c T with an executor of type @c Executor.
 template <typename Executor, typename T>
 BOOST_ASIO_NODISCARD inline executor_binder<decay_t<T>, Executor>
@@ -407,6 +451,20 @@ bind_executor(const Executor& ex, T&& t,
       executor_arg_t(), ex, static_cast<T&&>(t));
 }
 
+/// Create a partial completion token that associates an execution context's
+/// executor.
+template <typename ExecutionContext>
+BOOST_ASIO_NODISCARD inline partial_executor_binder<
+    typename ExecutionContext::executor_type>
+bind_executor(ExecutionContext& ctx,
+    constraint_t<
+      is_convertible<ExecutionContext&, execution_context&>::value
+    > = 0)
+{
+  return partial_executor_binder<typename ExecutionContext::executor_type>(
+      ctx.get_executor());
+}
+
 /// Associate an object of type @c T with an execution context's executor.
 template <typename ExecutionContext, typename T>
 BOOST_ASIO_NODISCARD inline executor_binder<decay_t<T>,
@@ -492,49 +550,48 @@ class async_result<executor_binder<T, Executor>, Signature> :
   }
 
   template <typename Initiation>
-  struct init_wrapper
+  struct init_wrapper : detail::initiation_base<Initiation>
   {
-    template <typename Init>
-    init_wrapper(const Executor& ex, Init&& init)
-      : ex_(ex),
-        initiation_(static_cast<Init&&>(init))
-    {
-    }
+    using detail::initiation_base<Initiation>::initiation_base;
 
     template <typename Handler, typename... Args>
-    void operator()(Handler&& handler, Args&&... args)
+    void operator()(Handler&& handler, const Executor& e, Args&&... args) &&
     {
-      static_cast<Initiation&&>(initiation_)(
+      static_cast<Initiation&&>(*this)(
           executor_binder<decay_t<Handler>, Executor>(
-            executor_arg_t(), ex_, static_cast<Handler&&>(handler)),
+            executor_arg_t(), e, static_cast<Handler&&>(handler)),
           static_cast<Args&&>(args)...);
     }
 
     template <typename Handler, typename... Args>
-    void operator()(Handler&& handler, Args&&... args) const
+    void operator()(Handler&& handler,
+        const Executor& e, Args&&... args) const &
     {
-      initiation_(
+      static_cast<const Initiation&>(*this)(
           executor_binder<decay_t<Handler>, Executor>(
-            executor_arg_t(), ex_, static_cast<Handler&&>(handler)),
+            executor_arg_t(), e, static_cast<Handler&&>(handler)),
           static_cast<Args&&>(args)...);
     }
-
-    Executor ex_;
-    Initiation initiation_;
   };
 
   template <typename Initiation, typename RawCompletionToken, typename... Args>
   static auto initiate(Initiation&& initiation,
       RawCompletionToken&& token, Args&&... args)
     -> decltype(
-      async_initiate<T, Signature>(
-        declval<init_wrapper<decay_t<Initiation>>>(),
-        token.get(), static_cast<Args&&>(args)...))
+      async_initiate<
+        conditional_t<
+          is_const<remove_reference_t<RawCompletionToken>>::value, const T, T>,
+        Signature>(
+          declval<init_wrapper<decay_t<Initiation>>>(),
+          token.get(), token.get_executor(), static_cast<Args&&>(args)...))
   {
-    return async_initiate<T, Signature>(
+    return async_initiate<
+      conditional_t<
+        is_const<remove_reference_t<RawCompletionToken>>::value, const T, T>,
+      Signature>(
         init_wrapper<decay_t<Initiation>>(
-          token.get_executor(), static_cast<Initiation&&>(initiation)),
-        token.get(), static_cast<Args&&>(args)...);
+          static_cast<Initiation&&>(initiation)),
+        token.get(), token.get_executor(), static_cast<Args&&>(args)...);
   }
 
 private:
@@ -542,6 +599,31 @@ class async_result<executor_binder<T, Executor>, Signature> :
   async_result& operator=(const async_result&) = delete;
 };
 
+template <typename Executor, typename... Signatures>
+struct async_result<partial_executor_binder<Executor>, Signatures...>
+{
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static auto initiate(Initiation&& initiation,
+      RawCompletionToken&& token, Args&&... args)
+    -> decltype(
+      async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        executor_binder<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          Executor>(executor_arg_t(), token.executor_,
+            default_completion_token_t<associated_executor_t<Initiation>>{}),
+        static_cast<Args&&>(args)...))
+  {
+    return async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        executor_binder<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          Executor>(executor_arg_t(), token.executor_,
+            default_completion_token_t<associated_executor_t<Initiation>>{}),
+        static_cast<Args&&>(args)...);
+  }
+};
+
 template <template <typename, typename> class Associator,
     typename T, typename Executor, typename DefaultCandidate>
 struct associator<Associator, executor_binder<T, Executor>, DefaultCandidate>
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/bind_immediate_executor.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/bind_immediate_executor.hpp
index b54288779b..fbf8c47325 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/bind_immediate_executor.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/bind_immediate_executor.hpp
@@ -16,10 +16,12 @@
 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
 
 #include <boost/asio/detail/config.hpp>
-#include <boost/asio/detail/type_traits.hpp>
+#include <boost/asio/associated_executor.hpp>
 #include <boost/asio/associated_immediate_executor.hpp>
 #include <boost/asio/associator.hpp>
 #include <boost/asio/async_result.hpp>
+#include <boost/asio/detail/initiation_base.hpp>
+#include <boost/asio/detail/type_traits.hpp>
 
 #include <boost/asio/detail/push_options.hpp>
 
@@ -366,6 +368,46 @@ class immediate_executor_binder
   T target_;
 };
 
+/// A function object type that adapts a @ref completion_token to specify that
+/// the completion handler should have the supplied executor as its associated
+/// immediate executor.
+/**
+ * May also be used directly as a completion token, in which case it adapts the
+ * asynchronous operation's default completion token (or boost::asio::deferred
+ * if no default is available).
+ */
+template <typename Executor>
+struct partial_immediate_executor_binder
+{
+  /// Constructor that specifies associated executor.
+  explicit partial_immediate_executor_binder(const Executor& ex)
+    : executor_(ex)
+  {
+  }
+
+  /// Adapt a @ref completion_token to specify that the completion handler
+  /// should have the executor as its associated immediate executor.
+  template <typename CompletionToken>
+  BOOST_ASIO_NODISCARD inline
+  constexpr immediate_executor_binder<decay_t<CompletionToken>, Executor>
+  operator()(CompletionToken&& completion_token) const
+  {
+    return immediate_executor_binder<decay_t<CompletionToken>, Executor>(
+        static_cast<CompletionToken&&>(completion_token), executor_);
+  }
+
+//private:
+  Executor executor_;
+};
+
+/// Create a partial completion token that associates an executor.
+template <typename Executor>
+BOOST_ASIO_NODISCARD inline partial_immediate_executor_binder<Executor>
+bind_immediate_executor(const Executor& ex)
+{
+  return partial_immediate_executor_binder<Executor>(ex);
+}
+
 /// Associate an object of type @c T with a immediate executor of type
 /// @c Executor.
 template <typename Executor, typename T>
@@ -450,52 +492,52 @@ class async_result<immediate_executor_binder<T, Executor>, Signature> :
   }
 
   template <typename Initiation>
-  struct init_wrapper
+  struct init_wrapper : detail::initiation_base<Initiation>
   {
-    template <typename Init>
-    init_wrapper(const Executor& e, Init&& init)
-      : executor_(e),
-        initiation_(static_cast<Init&&>(init))
-    {
-    }
+    using detail::initiation_base<Initiation>::initiation_base;
 
     template <typename Handler, typename... Args>
-    void operator()(Handler&& handler, Args&&... args)
+    void operator()(Handler&& handler, const Executor& e, Args&&... args) &&
     {
-      static_cast<Initiation&&>(initiation_)(
+      static_cast<Initiation&&>(*this)(
           immediate_executor_binder<
             decay_t<Handler>, Executor>(
-              executor_, static_cast<Handler&&>(handler)),
+              e, static_cast<Handler&&>(handler)),
           static_cast<Args&&>(args)...);
     }
 
     template <typename Handler, typename... Args>
-    void operator()(Handler&& handler, Args&&... args) const
+    void operator()(Handler&& handler,
+        const Executor& e, Args&&... args) const &
     {
-      initiation_(
+      static_cast<const Initiation&>(*this)(
           immediate_executor_binder<
             decay_t<Handler>, Executor>(
-              executor_, static_cast<Handler&&>(handler)),
+              e, static_cast<Handler&&>(handler)),
           static_cast<Args&&>(args)...);
     }
-
-    Executor executor_;
-    Initiation initiation_;
   };
 
   template <typename Initiation, typename RawCompletionToken, typename... Args>
   static auto initiate(Initiation&& initiation,
       RawCompletionToken&& token, Args&&... args)
     -> decltype(
-      async_initiate<T, Signature>(
-        declval<init_wrapper<decay_t<Initiation>>>(),
-        token.get(), static_cast<Args&&>(args)...))
+      async_initiate<
+        conditional_t<
+          is_const<remove_reference_t<RawCompletionToken>>::value, const T, T>,
+        Signature>(
+          declval<init_wrapper<decay_t<Initiation>>>(),
+          token.get(), token.get_immediate_executor(),
+          static_cast<Args&&>(args)...))
   {
-    return async_initiate<T, Signature>(
+    return async_initiate<
+      conditional_t<
+        is_const<remove_reference_t<RawCompletionToken>>::value, const T, T>,
+      Signature>(
         init_wrapper<decay_t<Initiation>>(
-          token.get_immediate_executor(),
           static_cast<Initiation&&>(initiation)),
-        token.get(), static_cast<Args&&>(args)...);
+        token.get(), token.get_immediate_executor(),
+        static_cast<Args&&>(args)...);
   }
 
 private:
@@ -505,6 +547,31 @@ class async_result<immediate_executor_binder<T, Executor>, Signature> :
   async_result<T, Signature> target_;
 };
 
+template <typename Executor, typename... Signatures>
+struct async_result<partial_immediate_executor_binder<Executor>, Signatures...>
+{
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static auto initiate(Initiation&& initiation,
+      RawCompletionToken&& token, Args&&... args)
+    -> decltype(
+      async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        immediate_executor_binder<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          Executor>(token.executor_,
+            default_completion_token_t<associated_executor_t<Initiation>>{}),
+        static_cast<Args&&>(args)...))
+  {
+    return async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        immediate_executor_binder<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          Executor>(token.executor_,
+            default_completion_token_t<associated_executor_t<Initiation>>{}),
+        static_cast<Args&&>(args)...);
+  }
+};
+
 template <template <typename, typename> class Associator,
     typename T, typename Executor, typename DefaultCandidate>
 struct associator<Associator,
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/buffer.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/buffer.hpp
index ed4bd66c15..c82507c67a 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/buffer.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/buffer.hpp
@@ -2731,7 +2731,7 @@ struct literal<'0', 'X', Chars...> :
 } // namespace detail
 
 /// Literal operator for creating const_buffer objects from string literals.
-inline BOOST_ASIO_CONST_BUFFER operator"" _buf(const char* data, std::size_t n)
+inline BOOST_ASIO_CONST_BUFFER operator ""_buf(const char* data, std::size_t n)
 {
   return BOOST_ASIO_CONST_BUFFER(data, n);
 }
@@ -2739,7 +2739,7 @@ inline BOOST_ASIO_CONST_BUFFER operator"" _buf(const char* data, std::size_t n)
 /// Literal operator for creating const_buffer objects from unbounded binary or
 /// hexadecimal integer literals.
 template <char... Chars>
-inline BOOST_ASIO_CONST_BUFFER operator"" _buf()
+inline BOOST_ASIO_CONST_BUFFER operator ""_buf()
 {
   return BOOST_ASIO_CONST_BUFFER(
       +detail::literal<Chars...>::data,
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/buffer_registration.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/buffer_registration.hpp
index fbab223688..6b412ca605 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/buffer_registration.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/buffer_registration.hpp
@@ -130,7 +130,7 @@ class buffer_registration
       service_->unregister_buffers();
 #endif // defined(BOOST_ASIO_HAS_IO_URING)
   }
-  
+
   /// Move assignment.
   buffer_registration& operator=(buffer_registration&& other) noexcept
   {
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/cancel_after.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/cancel_after.hpp
new file mode 100644
index 0000000000..220402b9dc
--- /dev/null
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/cancel_after.hpp
@@ -0,0 +1,303 @@
+//
+// cancel_after.hpp
+// ~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_CANCEL_AFTER_HPP
+#define BOOST_ASIO_CANCEL_AFTER_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/basic_waitable_timer.hpp>
+#include <boost/asio/cancellation_type.hpp>
+#include <boost/asio/detail/chrono.hpp>
+#include <boost/asio/detail/type_traits.hpp>
+#include <boost/asio/wait_traits.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+
+/// A @ref completion_token adapter that cancels an operation after a timeout.
+/**
+ * The cancel_after_t class is used to indicate that an asynchronous operation
+ * should be cancelled if not complete before the specified duration has
+ * elapsed.
+ */
+template <typename CompletionToken, typename Clock,
+    typename WaitTraits = boost::asio::wait_traits<Clock>>
+class cancel_after_t
+{
+public:
+  /// Constructor.
+  template <typename T>
+  cancel_after_t(T&& completion_token, const typename Clock::duration& timeout,
+      cancellation_type_t cancel_type = cancellation_type::terminal)
+    : token_(static_cast<T&&>(completion_token)),
+      timeout_(timeout),
+      cancel_type_(cancel_type)
+  {
+  }
+
+//private:
+  CompletionToken token_;
+  typename Clock::duration timeout_;
+  cancellation_type_t cancel_type_;
+};
+
+/// A @ref completion_token adapter that cancels an operation after a timeout.
+/**
+ * The cancel_after_timer class is used to indicate that an asynchronous
+ * operation should be cancelled if not complete before the specified duration
+ * has elapsed.
+ */
+template <typename CompletionToken, typename Clock,
+    typename WaitTraits = boost::asio::wait_traits<Clock>,
+    typename Executor = any_io_executor>
+class cancel_after_timer
+{
+public:
+  /// Constructor.
+  template <typename T>
+  cancel_after_timer(T&& completion_token,
+      basic_waitable_timer<Clock, WaitTraits, Executor>& timer,
+      const typename Clock::duration& timeout,
+      cancellation_type_t cancel_type = cancellation_type::terminal)
+    : token_(static_cast<T&&>(completion_token)),
+      timer_(timer),
+      timeout_(timeout),
+      cancel_type_(cancel_type)
+  {
+  }
+
+//private:
+  CompletionToken token_;
+  basic_waitable_timer<Clock, WaitTraits, Executor>& timer_;
+  typename Clock::duration timeout_;
+  cancellation_type_t cancel_type_;
+};
+
+/// A function object type that adapts a @ref completion_token to cancel an
+/// operation after a timeout.
+/**
+ * May also be used directly as a completion token, in which case it adapts the
+ * asynchronous operation's default completion token (or boost::asio::deferred
+ * if no default is available).
+ */
+template <typename Clock, typename WaitTraits = boost::asio::wait_traits<Clock>>
+class partial_cancel_after
+{
+public:
+  /// Constructor that specifies the timeout duration and cancellation type.
+  explicit partial_cancel_after(const typename Clock::duration& timeout,
+      cancellation_type_t cancel_type = cancellation_type::terminal)
+    : timeout_(timeout),
+      cancel_type_(cancel_type)
+  {
+  }
+
+  /// Adapt a @ref completion_token to specify that the completion handler
+  /// arguments should be combined into a single tuple argument.
+  template <typename CompletionToken>
+  BOOST_ASIO_NODISCARD inline
+  cancel_after_t<decay_t<CompletionToken>, Clock, WaitTraits>
+  operator()(CompletionToken&& completion_token) const
+  {
+    return cancel_after_t<decay_t<CompletionToken>, Clock, WaitTraits>(
+        static_cast<CompletionToken&&>(completion_token),
+        timeout_, cancel_type_);
+  }
+
+//private:
+  typename Clock::duration timeout_;
+  cancellation_type_t cancel_type_;
+};
+
+/// A function object type that adapts a @ref completion_token to cancel an
+/// operation after a timeout.
+/**
+ * May also be used directly as a completion token, in which case it adapts the
+ * asynchronous operation's default completion token (or boost::asio::deferred
+ * if no default is available).
+ */
+template <typename Clock, typename WaitTraits = boost::asio::wait_traits<Clock>,
+    typename Executor = any_io_executor>
+class partial_cancel_after_timer
+{
+public:
+  /// Constructor that specifies the timeout duration and cancellation type.
+  explicit partial_cancel_after_timer(
+      basic_waitable_timer<Clock, WaitTraits, Executor>& timer,
+      const typename Clock::duration& timeout,
+      cancellation_type_t cancel_type = cancellation_type::terminal)
+    : timer_(timer),
+      timeout_(timeout),
+      cancel_type_(cancel_type)
+  {
+  }
+
+  /// Adapt a @ref completion_token to specify that the completion handler
+  /// arguments should be combined into a single tuple argument.
+  template <typename CompletionToken>
+  BOOST_ASIO_NODISCARD inline
+  cancel_after_timer<decay_t<CompletionToken>, Clock, WaitTraits, Executor>
+  operator()(CompletionToken&& completion_token) const
+  {
+    return cancel_after_timer<decay_t<CompletionToken>,
+      Clock, WaitTraits, Executor>(
+        static_cast<CompletionToken&&>(completion_token),
+        timeout_, cancel_type_);
+  }
+
+//private:
+  basic_waitable_timer<Clock, WaitTraits, Executor>& timer_;
+  typename Clock::duration timeout_;
+  cancellation_type_t cancel_type_;
+};
+
+/// Create a partial completion token adapter that cancels an operation if not
+/// complete before the specified relative timeout has elapsed.
+/**
+ * @par Thread Safety
+ * When an asynchronous operation is used with cancel_after, a timer async_wait
+ * operation is performed in parallel to the main operation. If this parallel
+ * async_wait completes first, a cancellation request is emitted to cancel the
+ * main operation. Consequently, the application must ensure that the
+ * asynchronous operation is performed within an implicit or explicit strand.
+ */
+template <typename Rep, typename Period>
+BOOST_ASIO_NODISCARD inline partial_cancel_after<chrono::steady_clock>
+cancel_after(const chrono::duration<Rep, Period>& timeout,
+    cancellation_type_t cancel_type = cancellation_type::terminal)
+{
+  return partial_cancel_after<chrono::steady_clock>(timeout, cancel_type);
+}
+
+/// Create a partial completion token adapter that cancels an operation if not
+/// complete before the specified relative timeout has elapsed.
+/**
+ * @par Thread Safety
+ * When an asynchronous operation is used with cancel_after, a timer async_wait
+ * operation is performed in parallel to the main operation. If this parallel
+ * async_wait completes first, a cancellation request is emitted to cancel the
+ * main operation. Consequently, the application must ensure that the
+ * asynchronous operation is performed within an implicit or explicit strand.
+ */
+template <typename Clock, typename WaitTraits,
+    typename Executor, typename Rep, typename Period>
+BOOST_ASIO_NODISCARD inline
+partial_cancel_after_timer<Clock, WaitTraits, Executor>
+cancel_after(basic_waitable_timer<Clock, WaitTraits, Executor>& timer,
+    const chrono::duration<Rep, Period>& timeout,
+    cancellation_type_t cancel_type = cancellation_type::terminal)
+{
+  return partial_cancel_after_timer<Clock, WaitTraits, Executor>(
+      timer, timeout, cancel_type);
+}
+
+/// Adapt a @ref completion_token to cancel an operation if not complete before
+/// the specified relative timeout has elapsed.
+/**
+ * @par Thread Safety
+ * When an asynchronous operation is used with cancel_after, a timer async_wait
+ * operation is performed in parallel to the main operation. If this parallel
+ * async_wait completes first, a cancellation request is emitted to cancel the
+ * main operation. Consequently, the application must ensure that the
+ * asynchronous operation is performed within an implicit or explicit strand.
+ */
+template <typename Rep, typename Period, typename CompletionToken>
+BOOST_ASIO_NODISCARD inline
+cancel_after_t<decay_t<CompletionToken>, chrono::steady_clock>
+cancel_after(const chrono::duration<Rep, Period>& timeout,
+    CompletionToken&& completion_token)
+{
+  return cancel_after_t<decay_t<CompletionToken>, chrono::steady_clock>(
+      static_cast<CompletionToken&&>(completion_token),
+      timeout, cancellation_type::terminal);
+}
+
+/// Adapt a @ref completion_token to cancel an operation if not complete before
+/// the specified relative timeout has elapsed.
+/**
+ * @par Thread Safety
+ * When an asynchronous operation is used with cancel_after, a timer async_wait
+ * operation is performed in parallel to the main operation. If this parallel
+ * async_wait completes first, a cancellation request is emitted to cancel the
+ * main operation. Consequently, the application must ensure that the
+ * asynchronous operation is performed within an implicit or explicit strand.
+ */
+template <typename Rep, typename Period, typename CompletionToken>
+BOOST_ASIO_NODISCARD inline
+cancel_after_t<decay_t<CompletionToken>, chrono::steady_clock>
+cancel_after(const chrono::duration<Rep, Period>& timeout,
+    cancellation_type_t cancel_type, CompletionToken&& completion_token)
+{
+  return cancel_after_t<decay_t<CompletionToken>, chrono::steady_clock>(
+      static_cast<CompletionToken&&>(completion_token), timeout, cancel_type);
+}
+
+/// Adapt a @ref completion_token to cancel an operation if not complete before
+/// the specified relative timeout has elapsed.
+/**
+ * @par Thread Safety
+ * When an asynchronous operation is used with cancel_after, a timer async_wait
+ * operation is performed in parallel to the main operation. If this parallel
+ * async_wait completes first, a cancellation request is emitted to cancel the
+ * main operation. Consequently, the application must ensure that the
+ * asynchronous operation is performed within an implicit or explicit strand.
+ */
+template <typename Clock, typename WaitTraits, typename Executor,
+    typename Rep, typename Period, typename CompletionToken>
+BOOST_ASIO_NODISCARD inline
+cancel_after_timer<decay_t<CompletionToken>, Clock, WaitTraits, Executor>
+cancel_after(basic_waitable_timer<Clock, WaitTraits, Executor>& timer,
+    const chrono::duration<Rep, Period>& timeout,
+    CompletionToken&& completion_token)
+{
+  return cancel_after_timer<decay_t<CompletionToken>,
+    Clock, WaitTraits, Executor>(
+      static_cast<CompletionToken&&>(completion_token),
+      timer, timeout, cancellation_type::terminal);
+}
+
+/// Adapt a @ref completion_token to cancel an operation if not complete before
+/// the specified relative timeout has elapsed.
+/**
+ * @par Thread Safety
+ * When an asynchronous operation is used with cancel_after, a timer async_wait
+ * operation is performed in parallel to the main operation. If this parallel
+ * async_wait completes first, a cancellation request is emitted to cancel the
+ * main operation. Consequently, the application must ensure that the
+ * asynchronous operation is performed within an implicit or explicit strand.
+ */
+template <typename Clock, typename WaitTraits, typename Executor,
+    typename Rep, typename Period, typename CompletionToken>
+BOOST_ASIO_NODISCARD inline
+cancel_after_timer<decay_t<CompletionToken>, chrono::steady_clock>
+cancel_after(basic_waitable_timer<Clock, WaitTraits, Executor>& timer,
+    const chrono::duration<Rep, Period>& timeout,
+    cancellation_type_t cancel_type, CompletionToken&& completion_token)
+{
+  return cancel_after_timer<decay_t<CompletionToken>,
+    Clock, WaitTraits, Executor>(
+      static_cast<CompletionToken&&>(completion_token),
+      timer, timeout, cancel_type);
+}
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#include <boost/asio/impl/cancel_after.hpp>
+
+#endif // BOOST_ASIO_CANCEL_AFTER_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/cancel_at.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/cancel_at.hpp
new file mode 100644
index 0000000000..c9d39b13e5
--- /dev/null
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/cancel_at.hpp
@@ -0,0 +1,296 @@
+//
+// cancel_at.hpp
+// ~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_CANCEL_AT_HPP
+#define BOOST_ASIO_CANCEL_AT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/basic_waitable_timer.hpp>
+#include <boost/asio/cancellation_type.hpp>
+#include <boost/asio/detail/chrono.hpp>
+#include <boost/asio/detail/type_traits.hpp>
+#include <boost/asio/wait_traits.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+
+/// A @ref completion_token adapter that cancels an operation at a given time.
+/**
+ * The cancel_at_t class is used to indicate that an asynchronous operation
+ * should be cancelled if not complete at the specified absolute time.
+ */
+template <typename CompletionToken, typename Clock,
+    typename WaitTraits = boost::asio::wait_traits<Clock>>
+class cancel_at_t
+{
+public:
+  /// Constructor.
+  template <typename T>
+  cancel_at_t(T&& completion_token, const typename Clock::time_point& expiry,
+      cancellation_type_t cancel_type = cancellation_type::terminal)
+    : token_(static_cast<T&&>(completion_token)),
+      expiry_(expiry),
+      cancel_type_(cancel_type)
+  {
+  }
+
+//private:
+  CompletionToken token_;
+  typename Clock::time_point expiry_;
+  cancellation_type_t cancel_type_;
+};
+
+/// A @ref completion_token adapter that cancels an operation at a given time.
+/**
+ * The cancel_at_timer class is used to indicate that an asynchronous operation
+ * should be cancelled if not complete at the specified absolute time.
+ */
+template <typename CompletionToken, typename Clock,
+    typename WaitTraits = boost::asio::wait_traits<Clock>,
+    typename Executor = any_io_executor>
+class cancel_at_timer
+{
+public:
+  /// Constructor.
+  template <typename T>
+  cancel_at_timer(T&& completion_token,
+      basic_waitable_timer<Clock, WaitTraits, Executor>& timer,
+      const typename Clock::time_point& expiry,
+      cancellation_type_t cancel_type = cancellation_type::terminal)
+    : token_(static_cast<T&&>(completion_token)),
+      timer_(timer),
+      expiry_(expiry),
+      cancel_type_(cancel_type)
+  {
+  }
+
+//private:
+  CompletionToken token_;
+  basic_waitable_timer<Clock, WaitTraits, Executor>& timer_;
+  typename Clock::time_point expiry_;
+  cancellation_type_t cancel_type_;
+};
+
+/// A function object type that adapts a @ref completion_token to cancel an
+/// operation at a given time.
+/**
+ * May also be used directly as a completion token, in which case it adapts the
+ * asynchronous operation's default completion token (or boost::asio::deferred
+ * if no default is available).
+ */
+template <typename Clock, typename WaitTraits = boost::asio::wait_traits<Clock>>
+class partial_cancel_at
+{
+public:
+  /// Constructor that specifies the expiry and cancellation type.
+  explicit partial_cancel_at(const typename Clock::time_point& expiry,
+      cancellation_type_t cancel_type = cancellation_type::terminal)
+    : expiry_(expiry),
+      cancel_type_(cancel_type)
+  {
+  }
+
+  /// Adapt a @ref completion_token to specify that the completion handler
+  /// arguments should be combined into a single tuple argument.
+  template <typename CompletionToken>
+  BOOST_ASIO_NODISCARD inline
+  constexpr cancel_at_t<decay_t<CompletionToken>, Clock, WaitTraits>
+  operator()(CompletionToken&& completion_token) const
+  {
+    return cancel_at_t<decay_t<CompletionToken>, Clock, WaitTraits>(
+        static_cast<CompletionToken&&>(completion_token),
+        expiry_, cancel_type_);
+  }
+
+//private:
+  typename Clock::time_point expiry_;
+  cancellation_type_t cancel_type_;
+};
+
+/// A function object type that adapts a @ref completion_token to cancel an
+/// operation at a given time.
+/**
+ * May also be used directly as a completion token, in which case it adapts the
+ * asynchronous operation's default completion token (or boost::asio::deferred
+ * if no default is available).
+ */
+template <typename Clock, typename WaitTraits = boost::asio::wait_traits<Clock>,
+    typename Executor = any_io_executor>
+class partial_cancel_at_timer
+{
+public:
+  /// Constructor that specifies the expiry and cancellation type.
+  explicit partial_cancel_at_timer(
+      basic_waitable_timer<Clock, WaitTraits, Executor>& timer,
+      const typename Clock::time_point& expiry,
+      cancellation_type_t cancel_type = cancellation_type::terminal)
+    : timer_(timer),
+      expiry_(expiry),
+      cancel_type_(cancel_type)
+  {
+  }
+
+  /// Adapt a @ref completion_token to specify that the completion handler
+  /// arguments should be combined into a single tuple argument.
+  template <typename CompletionToken>
+  BOOST_ASIO_NODISCARD inline
+  cancel_at_timer<decay_t<CompletionToken>, Clock, WaitTraits, Executor>
+  operator()(CompletionToken&& completion_token) const
+  {
+    return cancel_at_timer<decay_t<CompletionToken>,
+      Clock, WaitTraits, Executor>(
+        static_cast<CompletionToken&&>(completion_token),
+        timer_, expiry_, cancel_type_);
+  }
+
+//private:
+  basic_waitable_timer<Clock, WaitTraits, Executor>& timer_;
+  typename Clock::time_point expiry_;
+  cancellation_type_t cancel_type_;
+};
+
+/// Create a partial completion token adapter that cancels an operation if not
+/// complete by the specified absolute time.
+/**
+ * @par Thread Safety
+ * When an asynchronous operation is used with cancel_at, a timer async_wait
+ * operation is performed in parallel to the main operation. If this parallel
+ * async_wait completes first, a cancellation request is emitted to cancel the
+ * main operation. Consequently, the application must ensure that the
+ * asynchronous operation is performed within an implicit or explicit strand.
+ */
+template <typename Clock, typename Duration>
+BOOST_ASIO_NODISCARD inline partial_cancel_at<Clock>
+cancel_at(const chrono::time_point<Clock, Duration>& expiry,
+    cancellation_type_t cancel_type = cancellation_type::terminal)
+{
+  return partial_cancel_at<Clock>(expiry, cancel_type);
+}
+
+/// Create a partial completion token adapter that cancels an operation if not
+/// complete by the specified absolute time.
+/**
+ * @par Thread Safety
+ * When an asynchronous operation is used with cancel_at, a timer async_wait
+ * operation is performed in parallel to the main operation. If this parallel
+ * async_wait completes first, a cancellation request is emitted to cancel the
+ * main operation. Consequently, the application must ensure that the
+ * asynchronous operation is performed within an implicit or explicit strand.
+ */
+template <typename Clock, typename WaitTraits,
+    typename Executor, typename Duration>
+BOOST_ASIO_NODISCARD inline partial_cancel_at_timer<Clock, WaitTraits, Executor>
+cancel_at(basic_waitable_timer<Clock, WaitTraits, Executor>& timer,
+    const chrono::time_point<Clock, Duration>& expiry,
+    cancellation_type_t cancel_type = cancellation_type::terminal)
+{
+  return partial_cancel_at_timer<Clock, WaitTraits, Executor>(
+      timer, expiry, cancel_type);
+}
+
+/// Adapt a @ref completion_token to cancel an operation if not complete by the
+/// specified absolute time.
+/**
+ * @par Thread Safety
+ * When an asynchronous operation is used with cancel_at, a timer async_wait
+ * operation is performed in parallel to the main operation. If this parallel
+ * async_wait completes first, a cancellation request is emitted to cancel the
+ * main operation. Consequently, the application must ensure that the
+ * asynchronous operation is performed within an implicit or explicit strand.
+ */
+template <typename CompletionToken, typename Clock, typename Duration>
+BOOST_ASIO_NODISCARD inline cancel_at_t<decay_t<CompletionToken>, Clock>
+cancel_at(const chrono::time_point<Clock, Duration>& expiry,
+    CompletionToken&& completion_token)
+{
+  return cancel_at_t<decay_t<CompletionToken>, Clock>(
+      static_cast<CompletionToken&&>(completion_token),
+      expiry, cancellation_type::terminal);
+}
+
+/// Adapt a @ref completion_token to cancel an operation if not complete by the
+/// specified absolute time.
+/**
+ * @par Thread Safety
+ * When an asynchronous operation is used with cancel_at, a timer async_wait
+ * operation is performed in parallel to the main operation. If this parallel
+ * async_wait completes first, a cancellation request is emitted to cancel the
+ * main operation. Consequently, the application must ensure that the
+ * asynchronous operation is performed within an implicit or explicit strand.
+ */
+template <typename CompletionToken, typename Clock, typename Duration>
+BOOST_ASIO_NODISCARD inline cancel_at_t<decay_t<CompletionToken>, Clock>
+cancel_at(const chrono::time_point<Clock, Duration>& expiry,
+    cancellation_type_t cancel_type, CompletionToken&& completion_token)
+{
+  return cancel_at_t<decay_t<CompletionToken>, Clock>(
+      static_cast<CompletionToken&&>(completion_token), expiry, cancel_type);
+}
+
+/// Adapt a @ref completion_token to cancel an operation if not complete by the
+/// specified absolute time.
+/**
+ * @par Thread Safety
+ * When an asynchronous operation is used with cancel_at, a timer async_wait
+ * operation is performed in parallel to the main operation. If this parallel
+ * async_wait completes first, a cancellation request is emitted to cancel the
+ * main operation. Consequently, the application must ensure that the
+ * asynchronous operation is performed within an implicit or explicit strand.
+ */
+template <typename CompletionToken, typename Clock,
+    typename WaitTraits, typename Executor, typename Duration>
+BOOST_ASIO_NODISCARD inline
+cancel_at_timer<decay_t<CompletionToken>, Clock, WaitTraits, Executor>
+cancel_at(basic_waitable_timer<Clock, WaitTraits, Executor>& timer,
+    const chrono::time_point<Clock, Duration>& expiry,
+    CompletionToken&& completion_token)
+{
+  return cancel_at_timer<decay_t<CompletionToken>, Clock, WaitTraits, Executor>(
+      static_cast<CompletionToken&&>(completion_token),
+      timer, expiry, cancellation_type::terminal);
+}
+
+/// Adapt a @ref completion_token to cancel an operation if not complete by the
+/// specified absolute time.
+/**
+ * @par Thread Safety
+ * When an asynchronous operation is used with cancel_at, a timer async_wait
+ * operation is performed in parallel to the main operation. If this parallel
+ * async_wait completes first, a cancellation request is emitted to cancel the
+ * main operation. Consequently, the application must ensure that the
+ * asynchronous operation is performed within an implicit or explicit strand.
+ */
+template <typename CompletionToken, typename Clock,
+    typename WaitTraits, typename Executor, typename Duration>
+BOOST_ASIO_NODISCARD inline
+cancel_at_timer<decay_t<CompletionToken>, Clock, WaitTraits, Executor>
+cancel_at(basic_waitable_timer<Clock, WaitTraits, Executor>& timer,
+    const chrono::time_point<Clock, Duration>& expiry,
+    cancellation_type_t cancel_type, CompletionToken&& completion_token)
+{
+  return cancel_at_timer<decay_t<CompletionToken>, Clock, WaitTraits, Executor>(
+      static_cast<CompletionToken&&>(completion_token),
+      timer, expiry, cancel_type);
+}
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#include <boost/asio/impl/cancel_at.hpp>
+
+#endif // BOOST_ASIO_CANCEL_AT_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/impl/co_composed.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/co_composed.hpp
similarity index 80%
rename from src/cxx_supportlib/vendor-modified/boost/asio/experimental/impl/co_composed.hpp
rename to src/cxx_supportlib/vendor-modified/boost/asio/co_composed.hpp
index 76b5b77221..6acd22c79c 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/impl/co_composed.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/co_composed.hpp
@@ -1,6 +1,6 @@
 //
-// experimental/impl/co_composed.hpp
-// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// co_composed.hpp
+// ~~~~~~~~~~~~~~~
 //
 // Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
 //
@@ -8,14 +8,17 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BOOST_ASIO_IMPL_EXPERIMENTAL_CO_COMPOSED_HPP
-#define BOOST_ASIO_IMPL_EXPERIMENTAL_CO_COMPOSED_HPP
+#ifndef BOOST_ASIO_CO_COMPOSED_HPP
+#define BOOST_ASIO_CO_COMPOSED_HPP
 
 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
 # pragma once
 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
 
 #include <boost/asio/detail/config.hpp>
+
+#if defined(BOOST_ASIO_HAS_CO_AWAIT) || defined(GENERATING_DOCUMENTATION)
+
 #include <new>
 #include <tuple>
 #include <variant>
@@ -45,7 +48,6 @@
 
 namespace boost {
 namespace asio {
-namespace experimental {
 namespace detail {
 
 #if defined(BOOST_ASIO_HAS_STD_COROUTINE)
@@ -75,7 +77,7 @@ class co_composed_handler_base;
 template <typename Executors, typename Handler, typename Return>
 class co_composed_promise;
 
-template <completion_signature... Signatures>
+template <BOOST_ASIO_COMPLETION_SIGNATURE... Signatures>
 class co_composed_returns
 {
 };
@@ -91,7 +93,7 @@ struct co_composed_completion : std::tuple<T&&...>
 {
   template <typename... U>
   co_composed_completion(U&&... u) noexcept
-    : std::tuple<T&&...>(std::forward<U>(u)...)
+    : std::tuple<T&&...>(static_cast<U&&>(u)...)
   {
   }
 };
@@ -313,8 +315,8 @@ class co_composed_state_cancellation
         (get_associated_cancellation_slot)(
           static_cast<co_composed_state<Executors, Handler, Return>*>(
             this)->handler()),
-        std::forward<InFilter>(in_filter),
-        std::forward<OutFilter>(out_filter));
+        static_cast<InFilter&&>(in_filter),
+        static_cast<OutFilter&&>(out_filter));
   }
 
   cancellation_type_t cancelled() const noexcept
@@ -469,7 +471,7 @@ class co_composed_state
   co_composed_state(composed_io_executors<Executors>&& executors,
       H&& h, co_composed_on_suspend& on_suspend)
     : work_(std::move(executors)),
-      handler_(std::forward<H>(h)),
+      handler_(static_cast<H&&>(h)),
       on_suspend_(&on_suspend)
   {
     this->reset_cancellation_state(enable_terminal_cancellation());
@@ -482,9 +484,9 @@ class co_composed_state
 
   template <typename... Args>
   [[nodiscard]] co_composed_completion<Args...> complete(Args&&... args)
-    requires requires { declval<Handler>()(std::forward<Args>(args)...); }
+    requires requires { declval<Handler>()(static_cast<Args&&>(args)...); }
   {
-    return co_composed_completion<Args...>(std::forward<Args>(args)...);
+    return co_composed_completion<Args...>(static_cast<Args&&>(args)...);
   }
 
   const Handler& handler() const noexcept
@@ -593,7 +595,7 @@ class co_composed_handler<Executors, Handler, Return, R(Args...)>
   template <typename... T>
   void operator()(T&&... args)
   {
-    result_type result(std::forward<T>(args)...);
+    result_type result(static_cast<T&&>(args)...);
     this->resume(&result);
   }
 
@@ -625,7 +627,7 @@ class co_composed_handler<Executors, Handler,
   template <typename... T>
   void operator()(const boost::system::error_code& ec, T&&... args)
   {
-    result_type result(ec, args_type(std::forward<T>(args)...));
+    result_type result(ec, args_type(static_cast<T&&>(args)...));
     this->resume(&result);
   }
 
@@ -658,7 +660,7 @@ class co_composed_handler<Executors, Handler,
   template <typename... T>
   void operator()(std::exception_ptr ex, T&&... args)
   {
-    result_type result(std::move(ex), args_type(std::forward<T>(args)...));
+    result_type result(std::move(ex), args_type(static_cast<T&&>(args)...));
     this->resume(&result);
   }
 
@@ -864,7 +866,7 @@ class co_composed_promise
 # endif // defined(BOOST_ASIO_HAS_SOURCE_LOCATION)
 #endif // defined(BOOST_ASIO_ENABLE_HANDLER_TRACKING)
         )
-        : op_(std::forward<Op>(op)),
+        : op_(static_cast<Op&&>(op)),
           promise_(promise)
 #if defined(BOOST_ASIO_ENABLE_HANDLER_TRACKING)
 # if defined(BOOST_ASIO_HAS_SOURCE_LOCATION)
@@ -895,7 +897,7 @@ class co_composed_promise
                   static_cast<awaitable*>(p)->location_.function_name()));
 # endif // defined(BOOST_ASIO_HAS_SOURCE_LOCATION)
 #endif // defined(BOOST_ASIO_ENABLE_HANDLER_TRACKING)
-              std::forward<Op>(static_cast<awaitable*>(p)->op_)(
+              static_cast<Op&&>(static_cast<awaitable*>(p)->op_)(
                   co_composed_handler<Executors, Handler,
                     Return, completion_signature_of_t<Op>>(
                       static_cast<awaitable*>(p)->promise_));
@@ -920,7 +922,7 @@ class co_composed_promise
     };
 
     state_.check_for_cancellation_on_transform();
-    return awaitable{std::forward<Op>(op), *this
+    return awaitable{static_cast<Op&&>(op), *this
 #if defined(BOOST_ASIO_ENABLE_HANDLER_TRACKING)
 # if defined(BOOST_ASIO_HAS_SOURCE_LOCATION)
         , location
@@ -961,7 +963,7 @@ class co_composed_promise
 
             Handler handler(std::move(a.promise_.state_.handler_));
             std::tuple<decay_t<Args>...> result(
-                std::move(static_cast<std::tuple<Args&&...>>(a.result_)));
+                std::move(static_cast<std::tuple<Args&&...>&>(a.result_)));
 
             co_composed_handler_base<Executors, Handler,
               Return>(std::move(composed_handler));
@@ -1014,7 +1016,7 @@ class initiate_co_composed
 
   template <typename I>
   initiate_co_composed(I&& impl, composed_io_executors<Executors>&& executors)
-    : implementation_(std::forward<I>(impl)),
+    : implementation_(static_cast<I&&>(impl)),
       executors_(std::move(executors))
   {
   }
@@ -1032,8 +1034,8 @@ class initiate_co_composed
     co_composed_on_suspend on_suspend{};
     implementation_(
         co_composed_state<Executors, handler_type, returns_type>(
-          executors_, std::forward<Handler>(handler), on_suspend),
-        std::forward<InitArgs>(init_args)...);
+          executors_, static_cast<Handler&&>(handler), on_suspend),
+        static_cast<InitArgs&&>(init_args)...);
     if (on_suspend.fn_)
       on_suspend.fn_(on_suspend.arg_);
   }
@@ -1046,8 +1048,8 @@ class initiate_co_composed
     co_composed_on_suspend on_suspend{};
     std::move(implementation_)(
         co_composed_state<Executors, handler_type, returns_type>(
-          std::move(executors_), std::forward<Handler>(handler), on_suspend),
-        std::forward<InitArgs>(init_args)...);
+          std::move(executors_), static_cast<Handler&&>(handler), on_suspend),
+        static_cast<InitArgs&&>(init_args)...);
     if (on_suspend.fn_)
       on_suspend.fn_(on_suspend.arg_);
   }
@@ -1057,46 +1059,74 @@ class initiate_co_composed
   composed_io_executors<Executors> executors_;
 };
 
+template <typename Implementation, typename... Signatures>
+class initiate_co_composed<Implementation, void(), Signatures...>
+{
+public:
+  template <typename I>
+  initiate_co_composed(I&& impl, composed_io_executors<void()>&&)
+    : implementation_(static_cast<I&&>(impl))
+  {
+  }
+
+  template <typename Handler, typename... InitArgs>
+  void operator()(Handler&& handler, InitArgs&&... init_args) const &
+  {
+    using handler_type = decay_t<Handler>;
+    using returns_type = co_composed_returns<Signatures...>;
+    co_composed_on_suspend on_suspend{};
+    implementation_(
+        co_composed_state<void(), handler_type, returns_type>(
+          composed_io_executors<void()>(),
+          static_cast<Handler&&>(handler), on_suspend),
+        static_cast<InitArgs&&>(init_args)...);
+    if (on_suspend.fn_)
+      on_suspend.fn_(on_suspend.arg_);
+  }
+
+  template <typename Handler, typename... InitArgs>
+  void operator()(Handler&& handler, InitArgs&&... init_args) &&
+  {
+    using handler_type = decay_t<Handler>;
+    using returns_type = co_composed_returns<Signatures...>;
+    co_composed_on_suspend on_suspend{};
+    std::move(implementation_)(
+        co_composed_state<void(), handler_type, returns_type>(
+          composed_io_executors<void()>(),
+          static_cast<Handler&&>(handler), on_suspend),
+        static_cast<InitArgs&&>(init_args)...);
+    if (on_suspend.fn_)
+      on_suspend.fn_(on_suspend.arg_);
+  }
+
+private:
+  Implementation implementation_;
+};
+
 template <typename... Signatures, typename Implementation, typename Executors>
-inline initiate_co_composed<Implementation, Executors, Signatures...>
+inline initiate_co_composed<decay_t<Implementation>, Executors, Signatures...>
 make_initiate_co_composed(Implementation&& implementation,
     composed_io_executors<Executors>&& executors)
 {
   return initiate_co_composed<
     decay_t<Implementation>, Executors, Signatures...>(
-        std::forward<Implementation>(implementation), std::move(executors));
+        static_cast<Implementation&&>(implementation), std::move(executors));
 }
 
 } // namespace detail
 
-template <completion_signature... Signatures,
-    typename Implementation, typename... IoObjectsOrExecutors>
-inline auto co_composed(Implementation&& implementation,
-    IoObjectsOrExecutors&&... io_objects_or_executors)
-{
-  return detail::make_initiate_co_composed<Signatures...>(
-      std::forward<Implementation>(implementation),
-      detail::make_composed_io_executors(
-        detail::get_composed_io_executor(
-          std::forward<IoObjectsOrExecutors>(
-            io_objects_or_executors))...));
-}
-
-} // namespace experimental
-
 #if !defined(GENERATING_DOCUMENTATION)
 
 template <template <typename, typename> class Associator,
     typename Executors, typename Handler, typename Return,
     typename Signature, typename DefaultCandidate>
 struct associator<Associator,
-    experimental::detail::co_composed_handler<
-      Executors, Handler, Return, Signature>,
+    detail::co_composed_handler<Executors, Handler, Return, Signature>,
     DefaultCandidate>
   : Associator<Handler, DefaultCandidate>
 {
   static typename Associator<Handler, DefaultCandidate>::type get(
-      const experimental::detail::co_composed_handler<
+      const detail::co_composed_handler<
         Executors, Handler, Return, Signature>& h) noexcept
   {
     return Associator<Handler, DefaultCandidate>::get(
@@ -1104,7 +1134,7 @@ struct associator<Associator,
   }
 
   static auto get(
-      const experimental::detail::co_composed_handler<
+      const detail::co_composed_handler<
         Executors, Handler, Return, Signature>& h,
       const DefaultCandidate& c) noexcept
     -> decltype(
@@ -1131,37 +1161,28 @@ namespace std { namespace experimental {
 template <typename C, typename Executors,
     typename Handler, typename Return, typename... Args>
 struct coroutine_traits<void, C&,
-    boost::asio::experimental::detail::co_composed_state<
-      Executors, Handler, Return>,
-    Args...>
+    boost::asio::detail::co_composed_state<Executors, Handler, Return>, Args...>
 {
   using promise_type =
-    boost::asio::experimental::detail::co_composed_promise<
-      Executors, Handler, Return>;
+    boost::asio::detail::co_composed_promise<Executors, Handler, Return>;
 };
 
 template <typename C, typename Executors,
     typename Handler, typename Return, typename... Args>
 struct coroutine_traits<void, C&&,
-    boost::asio::experimental::detail::co_composed_state<
-      Executors, Handler, Return>,
-    Args...>
+    boost::asio::detail::co_composed_state<Executors, Handler, Return>, Args...>
 {
   using promise_type =
-    boost::asio::experimental::detail::co_composed_promise<
-      Executors, Handler, Return>;
+    boost::asio::detail::co_composed_promise<Executors, Handler, Return>;
 };
 
 template <typename Executors, typename Handler,
     typename Return, typename... Args>
 struct coroutine_traits<void,
-    boost::asio::experimental::detail::co_composed_state<
-      Executors, Handler, Return>,
-    Args...>
+    boost::asio::detail::co_composed_state<Executors, Handler, Return>, Args...>
 {
   using promise_type =
-    boost::asio::experimental::detail::co_composed_promise<
-      Executors, Handler, Return>;
+    boost::asio::detail::co_composed_promise<Executors, Handler, Return>;
 };
 
 # if defined(BOOST_ASIO_HAS_STD_COROUTINE)
@@ -1171,6 +1192,132 @@ struct coroutine_traits<void,
 # endif // defined(BOOST_ASIO_HAS_STD_COROUTINE)
 #endif // !defined(GENERATING_DOCUMENTATION)
 
+namespace boost {
+namespace asio {
+
+/// Creates an initiation function object that may be used to launch a
+/// coroutine-based composed asynchronous operation.
+/**
+ * The co_composed utility simplifies the implementation of composed
+ * asynchronous operations by automatically adapting a coroutine to be an
+ * initiation function object for use with @c async_initiate. When awaiting
+ * asynchronous operations, the coroutine automatically uses a conforming
+ * intermediate completion handler.
+ *
+ * @param implementation A function object that contains the coroutine-based
+ * implementation of the composed asynchronous operation. The first argument to
+ * the function object represents the state of the operation, and may be used
+ * to test for cancellation. The remaining arguments are those passed to @c
+ * async_initiate after the completion token.
+ *
+ * @param io_objects_or_executors Zero or more I/O objects or I/O executors for
+ * which outstanding work must be maintained while the operation is incomplete.
+ *
+ * @par Per-Operation Cancellation
+ * By default, terminal per-operation cancellation is enabled for composed
+ * operations that use co_composed. To disable cancellation for the composed
+ * operation, or to alter its supported cancellation types, call the state's
+ * @c reset_cancellation_state function.
+ *
+ * @par Examples
+ * The following example illustrates manual error handling and explicit checks
+ * for cancellation. The completion handler is invoked via a @c co_yield to the
+ * state's @c complete function, which never returns.
+ *
+ * @code template <typename CompletionToken>
+ * auto async_echo(tcp::socket& socket,
+ *     CompletionToken&& token)
+ * {
+ *   return boost::asio::async_initiate<
+ *     CompletionToken, void(boost::system::error_code)>(
+ *       boost::asio::co_composed(
+ *         [](auto state, tcp::socket& socket) -> void
+ *         {
+ *           state.reset_cancellation_state(
+ *             boost::asio::enable_terminal_cancellation());
+ *
+ *           while (!state.cancelled())
+ *           {
+ *             char data[1024];
+ *             auto [e1, n1] =
+ *               co_await socket.async_read_some(
+ *                 boost::asio::buffer(data));
+ *
+ *             if (e1)
+ *               co_yield state.complete(e1);
+ *
+ *             if (!!state.cancelled())
+ *               co_yield state.complete(
+ *                 make_error_code(boost::asio::error::operation_aborted));
+ *
+ *             auto [e2, n2] =
+ *               co_await boost::asio::async_write(socket,
+ *                 boost::asio::buffer(data, n1));
+ *
+ *             if (e2)
+ *               co_yield state.complete(e2);
+ *           }
+ *         }, socket),
+ *       token, std::ref(socket));
+ * } @endcode
+ *
+ * This next example shows exception-based error handling and implicit checks
+ * for cancellation. The completion handler is invoked after returning from the
+ * coroutine via @c co_return. Valid @c co_return values are specified using
+ * completion signatures passed to the @c co_composed function.
+ *
+ * @code template <typename CompletionToken>
+ * auto async_echo(tcp::socket& socket,
+ *     CompletionToken&& token)
+ * {
+ *   return boost::asio::async_initiate<
+ *     CompletionToken, void(boost::system::error_code)>(
+ *       boost::asio::co_composed<
+ *         void(boost::system::error_code)>(
+ *           [](auto state, tcp::socket& socket) -> void
+ *           {
+ *             try
+ *             {
+ *               state.throw_if_cancelled(true);
+ *               state.reset_cancellation_state(
+ *                 boost::asio::enable_terminal_cancellation());
+ *
+ *               for (;;)
+ *               {
+ *                 char data[1024];
+ *                 std::size_t n = co_await socket.async_read_some(
+ *                     boost::asio::buffer(data));
+ *
+ *                 co_await boost::asio::async_write(socket,
+ *                     boost::asio::buffer(data, n));
+ *               }
+ *             }
+ *             catch (const boost::system::system_error& e)
+ *             {
+ *               co_return {e.code()};
+ *             }
+ *           }, socket),
+ *       token, std::ref(socket));
+ * } @endcode
+ */
+template <BOOST_ASIO_COMPLETION_SIGNATURE... Signatures,
+    typename Implementation, typename... IoObjectsOrExecutors>
+inline auto co_composed(Implementation&& implementation,
+    IoObjectsOrExecutors&&... io_objects_or_executors)
+{
+  return detail::make_initiate_co_composed<Signatures...>(
+      static_cast<Implementation&&>(implementation),
+      detail::make_composed_io_executors(
+        detail::get_composed_io_executor(
+          static_cast<IoObjectsOrExecutors&&>(
+            io_objects_or_executors))...));
+}
+
+} // namespace asio
+} // namespace boost
+
 #include <boost/asio/detail/pop_options.hpp>
 
-#endif // BOOST_ASIO_IMPL_EXPERIMENTAL_CO_COMPOSED_HPP
+#endif // defined(BOOST_ASIO_HAS_CO_AWAIT) || defined(GENERATING_DOCUMENTATION)
+
+#endif // BOOST_ASIO_CO_COMPOSED_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/completion_condition.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/completion_condition.hpp
index 8ad47d7c30..4cd9410924 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/completion_condition.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/completion_condition.hpp
@@ -17,6 +17,8 @@
 
 #include <boost/asio/detail/config.hpp>
 #include <cstddef>
+#include <boost/asio/detail/type_traits.hpp>
+#include <boost/system/error_code.hpp>
 
 #include <boost/asio/detail/push_options.hpp>
 
@@ -98,8 +100,55 @@ class transfer_exactly_t
   std::size_t size_;
 };
 
+template <typename T, typename = void>
+struct is_completion_condition_helper : false_type
+{
+};
+
+template <typename T>
+struct is_completion_condition_helper<T,
+    enable_if_t<
+      is_same<
+        result_of_t<T(boost::system::error_code, std::size_t)>,
+        bool
+      >::value
+    >
+  > : true_type
+{
+};
+
+template <typename T>
+struct is_completion_condition_helper<T,
+    enable_if_t<
+      is_same<
+        result_of_t<T(boost::system::error_code, std::size_t)>,
+        std::size_t
+      >::value
+    >
+  > : true_type
+{
+};
+
 } // namespace detail
 
+#if defined(GENERATING_DOCUMENTATION)
+
+/// Trait for determining whether a function object is a completion condition.
+template <typename T>
+struct is_completion_condition
+{
+  static constexpr bool value = automatically_determined;
+};
+
+#else // defined(GENERATING_DOCUMENTATION)
+
+template <typename T>
+struct is_completion_condition : detail::is_completion_condition_helper<T>
+{
+};
+
+#endif // defined(GENERATING_DOCUMENTATION)
+
 /**
  * @defgroup completion_condition Completion Condition Function Objects
  *
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/compose.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/compose.hpp
index b539850fb6..f23bd79e61 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/compose.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/compose.hpp
@@ -16,197 +16,12 @@
 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
 
 #include <boost/asio/detail/config.hpp>
-#include <boost/asio/associated_executor.hpp>
-#include <boost/asio/async_result.hpp>
-#include <boost/asio/detail/base_from_cancellation_state.hpp>
-#include <boost/asio/detail/composed_work.hpp>
-#include <boost/asio/detail/handler_cont_helpers.hpp>
-#include <boost/asio/detail/type_traits.hpp>
+#include <boost/asio/composed.hpp>
 
 #include <boost/asio/detail/push_options.hpp>
 
 namespace boost {
 namespace asio {
-namespace detail {
-
-template <typename Impl, typename Work, typename Handler, typename Signature>
-class composed_op;
-
-template <typename Impl, typename Work, typename Handler,
-    typename R, typename... Args>
-class composed_op<Impl, Work, Handler, R(Args...)>
-  : public base_from_cancellation_state<Handler>
-{
-public:
-  template <typename I, typename W, typename H>
-  composed_op(I&& impl,
-      W&& work,
-      H&& handler)
-    : base_from_cancellation_state<Handler>(
-        handler, enable_terminal_cancellation()),
-      impl_(static_cast<I&&>(impl)),
-      work_(static_cast<W&&>(work)),
-      handler_(static_cast<H&&>(handler)),
-      invocations_(0)
-  {
-  }
-
-  composed_op(composed_op&& other)
-    : base_from_cancellation_state<Handler>(
-        static_cast<base_from_cancellation_state<Handler>&&>(other)),
-      impl_(static_cast<Impl&&>(other.impl_)),
-      work_(static_cast<Work&&>(other.work_)),
-      handler_(static_cast<Handler&&>(other.handler_)),
-      invocations_(other.invocations_)
-  {
-  }
-
-  typedef typename composed_work_guard<
-    typename Work::head_type>::executor_type io_executor_type;
-
-  io_executor_type get_io_executor() const noexcept
-  {
-    return work_.head_.get_executor();
-  }
-
-  typedef associated_executor_t<Handler, io_executor_type> executor_type;
-
-  executor_type get_executor() const noexcept
-  {
-    return (get_associated_executor)(handler_, work_.head_.get_executor());
-  }
-
-  typedef associated_allocator_t<Handler, std::allocator<void>> allocator_type;
-
-  allocator_type get_allocator() const noexcept
-  {
-    return (get_associated_allocator)(handler_, std::allocator<void>());
-  }
-
-  template<typename... T>
-  void operator()(T&&... t)
-  {
-    if (invocations_ < ~0u)
-      ++invocations_;
-    this->get_cancellation_state().slot().clear();
-    impl_(*this, static_cast<T&&>(t)...);
-  }
-
-  void complete(Args... args)
-  {
-    this->work_.reset();
-    static_cast<Handler&&>(this->handler_)(static_cast<Args&&>(args)...);
-  }
-
-  void reset_cancellation_state()
-  {
-    base_from_cancellation_state<Handler>::reset_cancellation_state(handler_);
-  }
-
-  template <typename Filter>
-  void reset_cancellation_state(Filter&& filter)
-  {
-    base_from_cancellation_state<Handler>::reset_cancellation_state(handler_,
-        static_cast<Filter&&>(filter));
-  }
-
-  template <typename InFilter, typename OutFilter>
-  void reset_cancellation_state(InFilter&& in_filter,
-      OutFilter&& out_filter)
-  {
-    base_from_cancellation_state<Handler>::reset_cancellation_state(handler_,
-        static_cast<InFilter&&>(in_filter),
-        static_cast<OutFilter&&>(out_filter));
-  }
-
-  cancellation_type_t cancelled() const noexcept
-  {
-    return base_from_cancellation_state<Handler>::cancelled();
-  }
-
-//private:
-  Impl impl_;
-  Work work_;
-  Handler handler_;
-  unsigned invocations_;
-};
-
-template <typename Impl, typename Work, typename Handler, typename Signature>
-inline bool asio_handler_is_continuation(
-    composed_op<Impl, Work, Handler, Signature>* this_handler)
-{
-  return this_handler->invocations_ > 1 ? true
-    : boost_asio_handler_cont_helpers::is_continuation(
-        this_handler->handler_);
-}
-
-template <typename Signature, typename Executors>
-class initiate_composed_op
-{
-public:
-  typedef typename composed_io_executors<Executors>::head_type executor_type;
-
-  template <typename T>
-  explicit initiate_composed_op(int, T&& executors)
-    : executors_(static_cast<T&&>(executors))
-  {
-  }
-
-  executor_type get_executor() const noexcept
-  {
-    return executors_.head_;
-  }
-
-  template <typename Handler, typename Impl>
-  void operator()(Handler&& handler,
-      Impl&& impl) const
-  {
-    composed_op<decay_t<Impl>, composed_work<Executors>,
-      decay_t<Handler>, Signature>(
-        static_cast<Impl&&>(impl),
-        composed_work<Executors>(executors_),
-        static_cast<Handler&&>(handler))();
-  }
-
-private:
-  composed_io_executors<Executors> executors_;
-};
-
-template <typename Signature, typename Executors>
-inline initiate_composed_op<Signature, Executors> make_initiate_composed_op(
-    composed_io_executors<Executors>&& executors)
-{
-  return initiate_composed_op<Signature, Executors>(0,
-      static_cast<composed_io_executors<Executors>&&>(executors));
-}
-
-} // namespace detail
-
-#if !defined(GENERATING_DOCUMENTATION)
-
-template <template <typename, typename> class Associator,
-    typename Impl, typename Work, typename Handler,
-    typename Signature, typename DefaultCandidate>
-struct associator<Associator,
-    detail::composed_op<Impl, Work, Handler, Signature>,
-    DefaultCandidate>
-  : Associator<Handler, DefaultCandidate>
-{
-  static typename Associator<Handler, DefaultCandidate>::type get(
-      const detail::composed_op<Impl, Work, Handler, Signature>& h) noexcept
-  {
-    return Associator<Handler, DefaultCandidate>::get(h.handler_);
-  }
-
-  static auto get(const detail::composed_op<Impl, Work, Handler, Signature>& h,
-      const DefaultCandidate& c) noexcept
-    -> decltype(Associator<Handler, DefaultCandidate>::get(h.handler_, c))
-  {
-    return Associator<Handler, DefaultCandidate>::get(h.handler_, c);
-  }
-};
-
-#endif // !defined(GENERATING_DOCUMENTATION)
 
 /// Launch an asynchronous operation with a stateful implementation.
 /**
@@ -276,8 +91,8 @@ struct associator<Associator,
  * template <typename CompletionToken>
  * auto async_echo(tcp::socket& socket,
  *     boost::asio::mutable_buffer buffer,
- *     CompletionToken&& token) ->
- *   decltype(
+ *     CompletionToken&& token)
+ *   -> decltype(
  *     boost::asio::async_compose<CompletionToken,
  *       void(boost::system::error_code, std::size_t)>(
  *         std::declval<async_echo_implementation>(),
@@ -292,25 +107,19 @@ struct associator<Associator,
  */
 template <typename CompletionToken, typename Signature,
     typename Implementation, typename... IoObjectsOrExecutors>
-auto async_compose(Implementation&& implementation,
+inline auto async_compose(Implementation&& implementation,
     type_identity_t<CompletionToken>& token,
     IoObjectsOrExecutors&&... io_objects_or_executors)
   -> decltype(
     async_initiate<CompletionToken, Signature>(
-      detail::make_initiate_composed_op<Signature>(
-        detail::make_composed_io_executors(
-          detail::get_composed_io_executor(
-            static_cast<IoObjectsOrExecutors&&>(
-              io_objects_or_executors))...)),
-      token, static_cast<Implementation&&>(implementation)))
+      composed<Signature>(static_cast<Implementation&&>(implementation),
+        static_cast<IoObjectsOrExecutors&&>(io_objects_or_executors)...),
+      token))
 {
   return async_initiate<CompletionToken, Signature>(
-      detail::make_initiate_composed_op<Signature>(
-        detail::make_composed_io_executors(
-          detail::get_composed_io_executor(
-            static_cast<IoObjectsOrExecutors&&>(
-              io_objects_or_executors))...)),
-      token, static_cast<Implementation&&>(implementation));
+      composed<Signature>(static_cast<Implementation&&>(implementation),
+        static_cast<IoObjectsOrExecutors&&>(io_objects_or_executors)...),
+      token);
 }
 
 } // namespace asio
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/composed.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/composed.hpp
new file mode 100644
index 0000000000..bda1487759
--- /dev/null
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/composed.hpp
@@ -0,0 +1,415 @@
+//
+// composed.hpp
+// ~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_COMPOSED_HPP
+#define BOOST_ASIO_COMPOSED_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/associated_executor.hpp>
+#include <boost/asio/async_result.hpp>
+#include <boost/asio/detail/base_from_cancellation_state.hpp>
+#include <boost/asio/detail/composed_work.hpp>
+#include <boost/asio/detail/handler_cont_helpers.hpp>
+#include <boost/asio/detail/type_traits.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename Impl, typename Work,
+    typename Handler, typename... Signatures>
+class composed_op;
+
+template <typename Impl, typename Work, typename Handler>
+class composed_op<Impl, Work, Handler>
+  : public base_from_cancellation_state<Handler>
+{
+public:
+  template <typename I, typename W, typename H>
+  composed_op(I&& impl,
+      W&& work,
+      H&& handler)
+    : base_from_cancellation_state<Handler>(
+        handler, enable_terminal_cancellation()),
+      impl_(static_cast<I&&>(impl)),
+      work_(static_cast<W&&>(work)),
+      handler_(static_cast<H&&>(handler)),
+      invocations_(0)
+  {
+  }
+
+  composed_op(composed_op&& other)
+    : base_from_cancellation_state<Handler>(
+        static_cast<base_from_cancellation_state<Handler>&&>(other)),
+      impl_(static_cast<Impl&&>(other.impl_)),
+      work_(static_cast<Work&&>(other.work_)),
+      handler_(static_cast<Handler&&>(other.handler_)),
+      invocations_(other.invocations_)
+  {
+  }
+
+  typedef typename composed_work_guard<
+    typename Work::head_type>::executor_type io_executor_type;
+
+  io_executor_type get_io_executor() const noexcept
+  {
+    return work_.head_.get_executor();
+  }
+
+  typedef associated_executor_t<Handler, io_executor_type> executor_type;
+
+  executor_type get_executor() const noexcept
+  {
+    return (get_associated_executor)(handler_, work_.head_.get_executor());
+  }
+
+  typedef associated_allocator_t<Handler, std::allocator<void>> allocator_type;
+
+  allocator_type get_allocator() const noexcept
+  {
+    return (get_associated_allocator)(handler_, std::allocator<void>());
+  }
+
+  template <typename... T>
+  void operator()(T&&... t)
+  {
+    if (invocations_ < ~0u)
+      ++invocations_;
+    this->get_cancellation_state().slot().clear();
+    impl_(*this, static_cast<T&&>(t)...);
+  }
+
+  template <typename... Args>
+  auto complete(Args&&... args)
+    -> decltype(declval<Handler>()(static_cast<Args&&>(args)...))
+  {
+    return static_cast<Handler&&>(this->handler_)(static_cast<Args&&>(args)...);
+  }
+
+  void reset_cancellation_state()
+  {
+    base_from_cancellation_state<Handler>::reset_cancellation_state(handler_);
+  }
+
+  template <typename Filter>
+  void reset_cancellation_state(Filter&& filter)
+  {
+    base_from_cancellation_state<Handler>::reset_cancellation_state(handler_,
+        static_cast<Filter&&>(filter));
+  }
+
+  template <typename InFilter, typename OutFilter>
+  void reset_cancellation_state(InFilter&& in_filter,
+      OutFilter&& out_filter)
+  {
+    base_from_cancellation_state<Handler>::reset_cancellation_state(handler_,
+        static_cast<InFilter&&>(in_filter),
+        static_cast<OutFilter&&>(out_filter));
+  }
+
+  cancellation_type_t cancelled() const noexcept
+  {
+    return base_from_cancellation_state<Handler>::cancelled();
+  }
+
+//private:
+  Impl impl_;
+  Work work_;
+  Handler handler_;
+  unsigned invocations_;
+};
+
+template <typename Impl, typename Work, typename Handler,
+    typename R, typename... Args>
+class composed_op<Impl, Work, Handler, R(Args...)>
+  : public composed_op<Impl, Work, Handler>
+{
+public:
+  using composed_op<Impl, Work, Handler>::composed_op;
+
+  template <typename... T>
+  void operator()(T&&... t)
+  {
+    if (this->invocations_ < ~0u)
+      ++this->invocations_;
+    this->get_cancellation_state().slot().clear();
+    this->impl_(*this, static_cast<T&&>(t)...);
+  }
+
+  void complete(Args... args)
+  {
+    this->work_.reset();
+    static_cast<Handler&&>(this->handler_)(static_cast<Args&&>(args)...);
+  }
+};
+
+template <typename Impl, typename Work, typename Handler,
+    typename R, typename... Args, typename... Signatures>
+class composed_op<Impl, Work, Handler, R(Args...), Signatures...>
+  : public composed_op<Impl, Work, Handler, Signatures...>
+{
+public:
+  using composed_op<Impl, Work, Handler, Signatures...>::composed_op;
+
+  template <typename... T>
+  void operator()(T&&... t)
+  {
+    if (this->invocations_ < ~0u)
+      ++this->invocations_;
+    this->get_cancellation_state().slot().clear();
+    this->impl_(*this, static_cast<T&&>(t)...);
+  }
+
+  using composed_op<Impl, Work, Handler, Signatures...>::complete;
+
+  void complete(Args... args)
+  {
+    this->work_.reset();
+    static_cast<Handler&&>(this->handler_)(static_cast<Args&&>(args)...);
+  }
+};
+
+template <typename Impl, typename Work, typename Handler, typename Signature>
+inline bool asio_handler_is_continuation(
+    composed_op<Impl, Work, Handler, Signature>* this_handler)
+{
+  return this_handler->invocations_ > 1 ? true
+    : boost_asio_handler_cont_helpers::is_continuation(
+        this_handler->handler_);
+}
+
+template <typename Implementation, typename Executors, typename... Signatures>
+class initiate_composed
+{
+public:
+  typedef typename composed_io_executors<Executors>::head_type executor_type;
+
+  template <typename I>
+  initiate_composed(I&& impl, composed_io_executors<Executors>&& executors)
+    : implementation_(std::forward<I>(impl)),
+      executors_(std::move(executors))
+  {
+  }
+
+  executor_type get_executor() const noexcept
+  {
+    return executors_.head_;
+  }
+
+  template <typename Handler, typename... Args>
+  void operator()(Handler&& handler, Args&&... args) const &
+  {
+    composed_op<decay_t<Implementation>, composed_work<Executors>,
+      decay_t<Handler>, Signatures...>(implementation_,
+        composed_work<Executors>(executors_),
+        static_cast<Handler&&>(handler))(static_cast<Args&&>(args)...);
+  }
+
+  template <typename Handler, typename... Args>
+  void operator()(Handler&& handler, Args&&... args) &&
+  {
+    composed_op<decay_t<Implementation>, composed_work<Executors>,
+      decay_t<Handler>, Signatures...>(
+        static_cast<Implementation&&>(implementation_),
+        composed_work<Executors>(executors_),
+        static_cast<Handler&&>(handler))(static_cast<Args&&>(args)...);
+  }
+
+private:
+  Implementation implementation_;
+  composed_io_executors<Executors> executors_;
+};
+
+template <typename Implementation, typename... Signatures>
+class initiate_composed<Implementation, void(), Signatures...>
+{
+public:
+  template <typename I>
+  initiate_composed(I&& impl, composed_io_executors<void()>&&)
+    : implementation_(std::forward<I>(impl))
+  {
+  }
+
+  template <typename Handler, typename... Args>
+  void operator()(Handler&& handler, Args&&... args) const &
+  {
+    composed_op<decay_t<Implementation>, composed_work<void()>,
+      decay_t<Handler>, Signatures...>(implementation_,
+        composed_work<void()>(composed_io_executors<void()>()),
+        static_cast<Handler&&>(handler))(static_cast<Args&&>(args)...);
+  }
+
+  template <typename Handler, typename... Args>
+  void operator()(Handler&& handler, Args&&... args) &&
+  {
+    composed_op<decay_t<Implementation>, composed_work<void()>,
+      decay_t<Handler>, Signatures...>(
+        static_cast<Implementation&&>(implementation_),
+        composed_work<void()>(composed_io_executors<void()>()),
+        static_cast<Handler&&>(handler))(static_cast<Args&&>(args)...);
+  }
+
+private:
+  Implementation implementation_;
+};
+
+template <typename... Signatures, typename Implementation, typename Executors>
+inline initiate_composed<Implementation, Executors, Signatures...>
+make_initiate_composed(Implementation&& implementation,
+    composed_io_executors<Executors>&& executors)
+{
+  return initiate_composed<decay_t<Implementation>, Executors, Signatures...>(
+      static_cast<Implementation&&>(implementation),
+      static_cast<composed_io_executors<Executors>&&>(executors));
+}
+
+} // namespace detail
+
+#if !defined(GENERATING_DOCUMENTATION)
+
+template <template <typename, typename> class Associator,
+    typename Impl, typename Work, typename Handler,
+    typename Signature, typename DefaultCandidate>
+struct associator<Associator,
+    detail::composed_op<Impl, Work, Handler, Signature>,
+    DefaultCandidate>
+  : Associator<Handler, DefaultCandidate>
+{
+  static typename Associator<Handler, DefaultCandidate>::type get(
+      const detail::composed_op<Impl, Work, Handler, Signature>& h) noexcept
+  {
+    return Associator<Handler, DefaultCandidate>::get(h.handler_);
+  }
+
+  static auto get(const detail::composed_op<Impl, Work, Handler, Signature>& h,
+      const DefaultCandidate& c) noexcept
+    -> decltype(Associator<Handler, DefaultCandidate>::get(h.handler_, c))
+  {
+    return Associator<Handler, DefaultCandidate>::get(h.handler_, c);
+  }
+};
+
+#endif // !defined(GENERATING_DOCUMENTATION)
+
+/// Creates an initiation function object that may be used to launch an
+/// asynchronous operation with a stateful implementation.
+/**
+ * The @c composed function simplifies the implementation of composed
+ * asynchronous operations automatically by wrapping a stateful function object
+ * for use as an initiation function object.
+ *
+ * @param implementation A function object that contains the implementation of
+ * the composed asynchronous operation. The first argument to the function
+ * object is a non-const reference to the enclosing intermediate completion
+ * handler. The remaining arguments are any arguments that originate from the
+ * completion handlers of any asynchronous operations performed by the
+ * implementation.
+ *
+ * @param io_objects_or_executors Zero or more I/O objects or I/O executors for
+ * which outstanding work must be maintained.
+ *
+ * @par Per-Operation Cancellation
+ * By default, terminal per-operation cancellation is enabled for composed
+ * operations that are implemented using @c composed. To disable cancellation
+ * for the composed operation, or to alter its supported cancellation types,
+ * call the @c self object's @c reset_cancellation_state function.
+ *
+ * @par Example:
+ *
+ * @code struct async_echo_implementation
+ * {
+ *   tcp::socket& socket_;
+ *   boost::asio::mutable_buffer buffer_;
+ *   enum { starting, reading, writing } state_;
+ *
+ *   template <typename Self>
+ *   void operator()(Self& self,
+ *       boost::system::error_code error,
+ *       std::size_t n)
+ *   {
+ *     switch (state_)
+ *     {
+ *     case starting:
+ *       state_ = reading;
+ *       socket_.async_read_some(
+ *           buffer_, std::move(self));
+ *       break;
+ *     case reading:
+ *       if (error)
+ *       {
+ *         self.complete(error, 0);
+ *       }
+ *       else
+ *       {
+ *         state_ = writing;
+ *         boost::asio::async_write(socket_, buffer_,
+ *             boost::asio::transfer_exactly(n),
+ *             std::move(self));
+ *       }
+ *       break;
+ *     case writing:
+ *       self.complete(error, n);
+ *       break;
+ *     }
+ *   }
+ * };
+ *
+ * template <typename CompletionToken>
+ * auto async_echo(tcp::socket& socket,
+ *     boost::asio::mutable_buffer buffer,
+ *     CompletionToken&& token)
+ *   -> decltype(
+ *     boost::asio::async_initiate<CompletionToken,
+ *       void(boost::system::error_code, std::size_t)>(
+ *         boost::asio::composed(
+ *           async_echo_implementation{socket, buffer,
+ *             async_echo_implementation::starting}, socket),
+ *         token))
+ * {
+ *   return boost::asio::async_initiate<CompletionToken,
+ *     void(boost::system::error_code, std::size_t)>(
+ *       boost::asio::composed(
+ *         async_echo_implementation{socket, buffer,
+ *           async_echo_implementation::starting}, socket),
+ *       token, boost::system::error_code{}, 0);
+ * } @endcode
+ */
+template <BOOST_ASIO_COMPLETION_SIGNATURE... Signatures,
+    typename Implementation, typename... IoObjectsOrExecutors>
+inline auto composed(Implementation&& implementation,
+    IoObjectsOrExecutors&&... io_objects_or_executors)
+  -> decltype(
+    detail::make_initiate_composed<Signatures...>(
+      static_cast<Implementation&&>(implementation),
+      detail::make_composed_io_executors(
+        detail::get_composed_io_executor(
+          static_cast<IoObjectsOrExecutors&&>(
+            io_objects_or_executors))...)))
+{
+  return detail::make_initiate_composed<Signatures...>(
+      static_cast<Implementation&&>(implementation),
+      detail::make_composed_io_executors(
+        detail::get_composed_io_executor(
+          static_cast<IoObjectsOrExecutors&&>(
+            io_objects_or_executors))...));
+}
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_COMPOSE_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/connect.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/connect.hpp
index 5e8f5efc17..3d135750a5 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/connect.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/connect.hpp
@@ -32,34 +32,97 @@ namespace detail
   template <typename, typename> class initiate_async_range_connect;
   template <typename, typename> class initiate_async_iterator_connect;
 
-  char (&has_iterator_helper(...))[2];
+  template <typename T, typename = void, typename = void>
+  struct is_endpoint_sequence_helper : false_type
+  {
+  };
 
   template <typename T>
-  char has_iterator_helper(T*, typename T::iterator* = 0);
+  struct is_endpoint_sequence_helper<T,
+      void_t<
+        decltype(declval<T>().begin())
+      >,
+      void_t<
+        decltype(declval<T>().end())
+      >
+    > : true_type
+  {
+  };
 
-  template <typename T>
-  struct has_iterator_typedef
+  template <typename T, typename Iterator, typename = void>
+  struct is_connect_condition_helper : false_type
+  {
+  };
+
+  template <typename T, typename Iterator>
+  struct is_connect_condition_helper<T, Iterator,
+      enable_if_t<
+        is_same<
+          result_of_t<T(boost::system::error_code, Iterator)>,
+          Iterator
+        >::value
+      >
+    > : true_type
+  {
+  };
+
+  template <typename T, typename Iterator>
+  struct is_connect_condition_helper<T, Iterator,
+      enable_if_t<
+        is_same<
+          result_of_t<T(boost::system::error_code,
+            decltype(*declval<Iterator>()))>,
+          bool
+        >::value
+      >
+    > : true_type
   {
-    enum { value = (sizeof((has_iterator_helper)((T*)(0))) == 1) };
+  };
+
+  struct default_connect_condition
+  {
+    template <typename Endpoint>
+    bool operator()(const boost::system::error_code&, const Endpoint&)
+    {
+      return true;
+    }
   };
 } // namespace detail
 
+#if defined(GENERATING_DOCUMENTATION)
+
 /// Type trait used to determine whether a type is an endpoint sequence that can
 /// be used with with @c connect and @c async_connect.
 template <typename T>
 struct is_endpoint_sequence
 {
-#if defined(GENERATING_DOCUMENTATION)
   /// The value member is true if the type may be used as an endpoint sequence.
-  static const bool value;
-#else
-  enum
-  {
-    value = detail::has_iterator_typedef<T>::value
-  };
-#endif
+  static const bool value = automatically_determined;
+};
+
+/// Trait for determining whether a function object is a connect condition that
+/// can be used with @c connect and @c async_connect.
+template <typename T, typename Iterator>
+struct is_connect_condition
+{
+  /// The value member is true if the type may be used as a connect condition.
+  static constexpr bool value = automatically_determined;
+};
+
+#else // defined(GENERATING_DOCUMENTATION)
+
+template <typename T>
+struct is_endpoint_sequence : detail::is_endpoint_sequence_helper<T>
+{
+};
+
+template <typename T, typename Iterator>
+struct is_connect_condition : detail::is_connect_condition_helper<T, Iterator>
+{
 };
 
+#endif // defined(GENERATING_DOCUMENTATION)
+
 /**
  * @defgroup connect boost::asio::connect
  *
@@ -95,7 +158,9 @@ struct is_endpoint_sequence
 template <typename Protocol, typename Executor, typename EndpointSequence>
 typename Protocol::endpoint connect(basic_socket<Protocol, Executor>& s,
     const EndpointSequence& endpoints,
-    constraint_t<is_endpoint_sequence<EndpointSequence>::value> = 0);
+    constraint_t<
+      is_endpoint_sequence<EndpointSequence>::value
+    > = 0);
 
 /// Establishes a socket connection by trying each endpoint in a sequence.
 /**
@@ -130,7 +195,9 @@ typename Protocol::endpoint connect(basic_socket<Protocol, Executor>& s,
 template <typename Protocol, typename Executor, typename EndpointSequence>
 typename Protocol::endpoint connect(basic_socket<Protocol, Executor>& s,
     const EndpointSequence& endpoints, boost::system::error_code& ec,
-    constraint_t<is_endpoint_sequence<EndpointSequence>::value> = 0);
+    constraint_t<
+      is_endpoint_sequence<EndpointSequence>::value
+    > = 0);
 
 #if !defined(BOOST_ASIO_NO_DEPRECATED)
 /// (Deprecated: Use range overload.) Establishes a socket connection by trying
@@ -159,7 +226,9 @@ typename Protocol::endpoint connect(basic_socket<Protocol, Executor>& s,
  */
 template <typename Protocol, typename Executor, typename Iterator>
 Iterator connect(basic_socket<Protocol, Executor>& s, Iterator begin,
-    constraint_t<!is_endpoint_sequence<Iterator>::value> = 0);
+    constraint_t<
+      !is_endpoint_sequence<Iterator>::value
+    > = 0);
 
 /// (Deprecated: Use range overload.) Establishes a socket connection by trying
 /// each endpoint in a sequence.
@@ -188,7 +257,9 @@ Iterator connect(basic_socket<Protocol, Executor>& s, Iterator begin,
 template <typename Protocol, typename Executor, typename Iterator>
 Iterator connect(basic_socket<Protocol, Executor>& s,
     Iterator begin, boost::system::error_code& ec,
-    constraint_t<!is_endpoint_sequence<Iterator>::value> = 0);
+    constraint_t<
+      !is_endpoint_sequence<Iterator>::value
+    > = 0);
 #endif // !defined(BOOST_ASIO_NO_DEPRECATED)
 
 /// Establishes a socket connection by trying each endpoint in a sequence.
@@ -314,7 +385,13 @@ template <typename Protocol, typename Executor,
     typename EndpointSequence, typename ConnectCondition>
 typename Protocol::endpoint connect(basic_socket<Protocol, Executor>& s,
     const EndpointSequence& endpoints, ConnectCondition connect_condition,
-    constraint_t<is_endpoint_sequence<EndpointSequence>::value> = 0);
+    constraint_t<
+      is_endpoint_sequence<EndpointSequence>::value
+    > = 0,
+    constraint_t<
+      is_connect_condition<ConnectCondition,
+        decltype(declval<const EndpointSequence&>().begin())>::value
+    > = 0);
 
 /// Establishes a socket connection by trying each endpoint in a sequence.
 /**
@@ -381,7 +458,13 @@ template <typename Protocol, typename Executor,
 typename Protocol::endpoint connect(basic_socket<Protocol, Executor>& s,
     const EndpointSequence& endpoints, ConnectCondition connect_condition,
     boost::system::error_code& ec,
-    constraint_t<is_endpoint_sequence<EndpointSequence>::value> = 0);
+    constraint_t<
+      is_endpoint_sequence<EndpointSequence>::value
+    > = 0,
+    constraint_t<
+      is_connect_condition<ConnectCondition,
+        decltype(declval<const EndpointSequence&>().begin())>::value
+    > = 0);
 
 #if !defined(BOOST_ASIO_NO_DEPRECATED)
 /// (Deprecated: Use range overload.) Establishes a socket connection by trying
@@ -423,7 +506,12 @@ template <typename Protocol, typename Executor,
     typename Iterator, typename ConnectCondition>
 Iterator connect(basic_socket<Protocol, Executor>& s,
     Iterator begin, ConnectCondition connect_condition,
-    constraint_t<!is_endpoint_sequence<Iterator>::value> = 0);
+    constraint_t<
+      !is_endpoint_sequence<Iterator>::value
+    > = 0,
+    constraint_t<
+      is_connect_condition<ConnectCondition, Iterator>::value
+    > = 0);
 
 /// (Deprecated: Use range overload.) Establishes a socket connection by trying
 /// each endpoint in a sequence.
@@ -464,7 +552,12 @@ template <typename Protocol, typename Executor,
     typename Iterator, typename ConnectCondition>
 Iterator connect(basic_socket<Protocol, Executor>& s, Iterator begin,
     ConnectCondition connect_condition, boost::system::error_code& ec,
-    constraint_t<!is_endpoint_sequence<Iterator>::value> = 0);
+    constraint_t<
+      !is_endpoint_sequence<Iterator>::value
+    > = 0,
+    constraint_t<
+      is_connect_condition<ConnectCondition, Iterator>::value
+    > = 0);
 #endif // !defined(BOOST_ASIO_NO_DEPRECATED)
 
 /// Establishes a socket connection by trying each endpoint in a sequence.
@@ -524,7 +617,10 @@ Iterator connect(basic_socket<Protocol, Executor>& s, Iterator begin,
 template <typename Protocol, typename Executor,
     typename Iterator, typename ConnectCondition>
 Iterator connect(basic_socket<Protocol, Executor>& s, Iterator begin,
-    Iterator end, ConnectCondition connect_condition);
+    Iterator end, ConnectCondition connect_condition,
+    constraint_t<
+      is_connect_condition<ConnectCondition, Iterator>::value
+    > = 0);
 
 /// Establishes a socket connection by trying each endpoint in a sequence.
 /**
@@ -593,7 +689,10 @@ template <typename Protocol, typename Executor,
     typename Iterator, typename ConnectCondition>
 Iterator connect(basic_socket<Protocol, Executor>& s,
     Iterator begin, Iterator end, ConnectCondition connect_condition,
-    boost::system::error_code& ec);
+    boost::system::error_code& ec,
+    constraint_t<
+      is_connect_condition<ConnectCondition, Iterator>::value
+    > = 0);
 
 /*@}*/
 
@@ -637,7 +736,7 @@ Iterator connect(basic_socket<Protocol, Executor>& s,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, typename Protocol::endpoint) @endcode
@@ -686,15 +785,27 @@ template <typename Protocol, typename Executor, typename EndpointSequence,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       typename Protocol::endpoint)) RangeConnectToken
         = default_completion_token_t<Executor>>
-auto async_connect(basic_socket<Protocol, Executor>& s,
+inline auto async_connect(basic_socket<Protocol, Executor>& s,
     const EndpointSequence& endpoints,
     RangeConnectToken&& token = default_completion_token_t<Executor>(),
-    constraint_t<is_endpoint_sequence<EndpointSequence>::value> = 0)
+    constraint_t<
+      is_endpoint_sequence<EndpointSequence>::value
+    > = 0,
+    constraint_t<
+      !is_connect_condition<RangeConnectToken,
+        decltype(declval<const EndpointSequence&>().begin())>::value
+    > = 0)
   -> decltype(
     async_initiate<RangeConnectToken,
       void (boost::system::error_code, typename Protocol::endpoint)>(
         declval<detail::initiate_async_range_connect<Protocol, Executor>>(),
-        token, endpoints, declval<detail::default_connect_condition>()));
+        token, endpoints, declval<detail::default_connect_condition>()))
+{
+  return async_initiate<RangeConnectToken,
+    void (boost::system::error_code, typename Protocol::endpoint)>(
+      detail::initiate_async_range_connect<Protocol, Executor>(s),
+      token, endpoints, detail::default_connect_condition());
+}
 
 #if !defined(BOOST_ASIO_NO_DEPRECATED)
 /// (Deprecated: Use range overload.) Asynchronously establishes a socket
@@ -729,7 +840,7 @@ auto async_connect(basic_socket<Protocol, Executor>& s,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, Iterator) @endcode
@@ -751,15 +862,29 @@ auto async_connect(basic_socket<Protocol, Executor>& s,
 template <typename Protocol, typename Executor, typename Iterator,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       Iterator)) IteratorConnectToken = default_completion_token_t<Executor>>
-auto async_connect(basic_socket<Protocol, Executor>& s, Iterator begin,
+inline auto async_connect(basic_socket<Protocol, Executor>& s, Iterator begin,
     IteratorConnectToken&& token = default_completion_token_t<Executor>(),
-    constraint_t<!is_endpoint_sequence<Iterator>::value> = 0)
+    constraint_t<
+      !is_endpoint_sequence<Iterator>::value
+    > = 0,
+    constraint_t<
+      !is_same<Iterator, decay_t<IteratorConnectToken>>::value
+    > = 0,
+    constraint_t<
+      !is_connect_condition<IteratorConnectToken, Iterator>::value
+    > = 0)
   -> decltype(
     async_initiate<IteratorConnectToken,
       void (boost::system::error_code, Iterator)>(
         declval<detail::initiate_async_iterator_connect<Protocol, Executor>>(),
         token, begin, Iterator(),
-        declval<detail::default_connect_condition>()));
+        declval<detail::default_connect_condition>()))
+{
+  return async_initiate<IteratorConnectToken,
+    void (boost::system::error_code, Iterator)>(
+      detail::initiate_async_iterator_connect<Protocol, Executor>(s),
+      token, begin, Iterator(), detail::default_connect_condition());
+}
 #endif // !defined(BOOST_ASIO_NO_DEPRECATED)
 
 /// Asynchronously establishes a socket connection by trying each endpoint in a
@@ -796,7 +921,7 @@ auto async_connect(basic_socket<Protocol, Executor>& s, Iterator begin,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, Iterator) @endcode
@@ -830,14 +955,23 @@ auto async_connect(basic_socket<Protocol, Executor>& s, Iterator begin,
 template <typename Protocol, typename Executor, typename Iterator,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       Iterator)) IteratorConnectToken = default_completion_token_t<Executor>>
-auto async_connect(
+inline auto async_connect(
     basic_socket<Protocol, Executor>& s, Iterator begin, Iterator end,
-    IteratorConnectToken&& token = default_completion_token_t<Executor>())
+    IteratorConnectToken&& token = default_completion_token_t<Executor>(),
+    constraint_t<
+      !is_connect_condition<IteratorConnectToken, Iterator>::value
+    > = 0)
   -> decltype(
     async_initiate<IteratorConnectToken,
       void (boost::system::error_code, Iterator)>(
         declval<detail::initiate_async_iterator_connect<Protocol, Executor>>(),
-        token, begin, end, declval<detail::default_connect_condition>()));
+        token, begin, end, declval<detail::default_connect_condition>()))
+{
+  return async_initiate<IteratorConnectToken,
+    void (boost::system::error_code, Iterator)>(
+      detail::initiate_async_iterator_connect<Protocol, Executor>(s),
+      token, begin, end, detail::default_connect_condition());
+}
 
 /// Asynchronously establishes a socket connection by trying each endpoint in a
 /// sequence.
@@ -882,7 +1016,7 @@ auto async_connect(
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, typename Protocol::endpoint) @endcode
@@ -955,15 +1089,27 @@ template <typename Protocol, typename Executor,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       typename Protocol::endpoint)) RangeConnectToken
         = default_completion_token_t<Executor>>
-auto async_connect(basic_socket<Protocol, Executor>& s,
+inline auto async_connect(basic_socket<Protocol, Executor>& s,
     const EndpointSequence& endpoints, ConnectCondition connect_condition,
     RangeConnectToken&& token = default_completion_token_t<Executor>(),
-    constraint_t<is_endpoint_sequence<EndpointSequence>::value> = 0)
+    constraint_t<
+      is_endpoint_sequence<EndpointSequence>::value
+    > = 0,
+    constraint_t<
+      is_connect_condition<ConnectCondition,
+        decltype(declval<const EndpointSequence&>().begin())>::value
+    > = 0)
   -> decltype(
     async_initiate<RangeConnectToken,
       void (boost::system::error_code, typename Protocol::endpoint)>(
         declval<detail::initiate_async_range_connect<Protocol, Executor>>(),
-        token, endpoints, connect_condition));
+        token, endpoints, connect_condition))
+{
+  return async_initiate<RangeConnectToken,
+    void (boost::system::error_code, typename Protocol::endpoint)>(
+      detail::initiate_async_range_connect<Protocol, Executor>(s),
+      token, endpoints, connect_condition);
+}
 
 #if !defined(BOOST_ASIO_NO_DEPRECATED)
 /// (Deprecated: Use range overload.) Asynchronously establishes a socket
@@ -1009,7 +1155,7 @@ auto async_connect(basic_socket<Protocol, Executor>& s,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, Iterator) @endcode
@@ -1032,15 +1178,26 @@ template <typename Protocol, typename Executor,
     typename Iterator, typename ConnectCondition,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       Iterator)) IteratorConnectToken = default_completion_token_t<Executor>>
-auto async_connect(basic_socket<Protocol, Executor>& s,
+inline auto async_connect(basic_socket<Protocol, Executor>& s,
     Iterator begin, ConnectCondition connect_condition,
     IteratorConnectToken&& token = default_completion_token_t<Executor>(),
-    constraint_t<!is_endpoint_sequence<Iterator>::value> = 0)
+    constraint_t<
+      !is_endpoint_sequence<Iterator>::value
+    > = 0,
+    constraint_t<
+      is_connect_condition<ConnectCondition, Iterator>::value
+    > = 0)
   -> decltype(
     async_initiate<IteratorConnectToken,
       void (boost::system::error_code, Iterator)>(
         declval<detail::initiate_async_iterator_connect<Protocol, Executor>>(),
-        token, begin, Iterator(), connect_condition));
+        token, begin, Iterator(), connect_condition))
+{
+  return async_initiate<IteratorConnectToken,
+    void (boost::system::error_code, Iterator)>(
+      detail::initiate_async_iterator_connect<Protocol, Executor>(s),
+      token, begin, Iterator(), connect_condition);
+}
 #endif // !defined(BOOST_ASIO_NO_DEPRECATED)
 
 /// Asynchronously establishes a socket connection by trying each endpoint in a
@@ -1088,7 +1245,7 @@ auto async_connect(basic_socket<Protocol, Executor>& s,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, Iterator) @endcode
@@ -1161,14 +1318,23 @@ template <typename Protocol, typename Executor,
     typename Iterator, typename ConnectCondition,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       Iterator)) IteratorConnectToken = default_completion_token_t<Executor>>
-auto async_connect(basic_socket<Protocol, Executor>& s,
+inline auto async_connect(basic_socket<Protocol, Executor>& s,
     Iterator begin, Iterator end, ConnectCondition connect_condition,
-    IteratorConnectToken&& token = default_completion_token_t<Executor>())
+    IteratorConnectToken&& token = default_completion_token_t<Executor>(),
+    constraint_t<
+      is_connect_condition<ConnectCondition, Iterator>::value
+    > = 0)
   -> decltype(
     async_initiate<IteratorConnectToken,
       void (boost::system::error_code, Iterator)>(
         declval<detail::initiate_async_iterator_connect<Protocol, Executor>>(),
-        token, begin, end, connect_condition));
+        token, begin, end, connect_condition))
+{
+  return async_initiate<IteratorConnectToken,
+    void (boost::system::error_code, Iterator)>(
+      detail::initiate_async_iterator_connect<Protocol, Executor>(s),
+      token, begin, end, connect_condition);
+}
 
 /*@}*/
 
@@ -1179,4 +1345,4 @@ auto async_connect(basic_socket<Protocol, Executor>& s,
 
 #include <boost/asio/impl/connect.hpp>
 
-#endif
+#endif // BOOST_ASIO_CONNECT_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/coroutine.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/coroutine.hpp
index 72ddd21e5c..7f37866c20 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/coroutine.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/coroutine.hpp
@@ -201,7 +201,7 @@ class coroutine_ref;
  * The @c fork pseudo-keyword is used when "forking" a coroutine, i.e. splitting
  * it into two (or more) copies. One use of @c fork is in a server, where a new
  * coroutine is created to handle each client connection:
- * 
+ *
  * @code reenter (this)
  * {
  *   do
@@ -212,9 +212,9 @@ class coroutine_ref;
  *   } while (is_parent());
  *   ... client-specific handling follows ...
  * } @endcode
- * 
+ *
  * The logical steps involved in a @c fork are:
- * 
+ *
  * @li @c fork saves the current state of the coroutine.
  * @li The statement creates a copy of the coroutine and either executes it
  *     immediately or schedules it for later execution.
@@ -259,7 +259,6 @@ class coroutine
   int value_;
 };
 
-
 namespace detail {
 
 class coroutine_ref
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/default_completion_token.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/default_completion_token.hpp
new file mode 100644
index 0000000000..f7a41ccff7
--- /dev/null
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/default_completion_token.hpp
@@ -0,0 +1,91 @@
+//
+// default_completion_token.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_HPP
+#define BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/detail/type_traits.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+
+class deferred_t;
+
+namespace detail {
+
+template <typename T, typename = void>
+struct default_completion_token_impl
+{
+  typedef deferred_t type;
+};
+
+template <typename T>
+struct default_completion_token_impl<T,
+    void_t<typename T::default_completion_token_type>
+  >
+{
+  typedef typename T::default_completion_token_type type;
+};
+
+} // namespace detail
+
+#if defined(GENERATING_DOCUMENTATION)
+
+/// Traits type used to determine the default completion token type associated
+/// with a type (such as an executor).
+/**
+ * A program may specialise this traits type if the @c T template parameter in
+ * the specialisation is a user-defined type.
+ *
+ * Specialisations of this trait may provide a nested typedef @c type, which is
+ * a default-constructible completion token type.
+ *
+ * If not otherwise specialised, the default completion token type is
+ * boost::asio::deferred_t.
+ */
+template <typename T>
+struct default_completion_token
+{
+  /// If @c T has a nested type @c default_completion_token_type,
+  /// <tt>T::default_completion_token_type</tt>. Otherwise the typedef @c type
+  /// is boost::asio::deferred_t.
+  typedef see_below type;
+};
+#else
+template <typename T>
+struct default_completion_token
+  : detail::default_completion_token_impl<T>
+{
+};
+#endif
+
+template <typename T>
+using default_completion_token_t = typename default_completion_token<T>::type;
+
+#define BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(e) \
+  = typename ::boost::asio::default_completion_token<e>::type
+#define BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(e) \
+  = typename ::boost::asio::default_completion_token<e>::type()
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#include <boost/asio/deferred.hpp>
+
+#endif // BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/deferred.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/deferred.hpp
index 4e69a494fc..dfb8e51feb 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/deferred.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/deferred.hpp
@@ -185,7 +185,7 @@ template <typename Function>
 class deferred_function
 {
 public:
-  /// Constructor. 
+  /// Constructor.
   template <typename F>
   constexpr explicit deferred_function(deferred_init_tag, F&& function)
     : function_(static_cast<F&&>(function))
@@ -326,7 +326,8 @@ class BOOST_ASIO_NODISCARD deferred_async_operation
       detail::index_sequence<I...>) const &
     -> decltype(
       async_initiate<CompletionToken, Signature>(
-        initiation_t(initiation_), token, std::get<I>(init_args_)...))
+        conditional_t<true, initiation_t, CompletionToken>(initiation_),
+        token, std::get<I>(init_args_)...))
   {
     return async_initiate<CompletionToken, Signature>(
         initiation_t(initiation_), token, std::get<I>(init_args_)...);
@@ -593,8 +594,11 @@ struct is_deferred<deferred_conditional<OnTrue, OnFalse>> : true_type
  * The deferred_t class is used to indicate that an asynchronous operation
  * should return a function object which is itself an initiation function. A
  * deferred_t object may be passed as a completion token to an asynchronous
- * operation, typically using the special value @c boost::asio::deferred. For
- * example:
+ * operation, typically as the default completion token:
+ *
+ * @code auto my_deferred_op = my_socket.async_read_some(my_buffer); @endcode
+ *
+ * or by explicitly passing the special value @c boost::asio::deferred:
  *
  * @code auto my_deferred_op
  *   = my_socket.async_read_some(my_buffer,
@@ -705,7 +709,7 @@ inline auto operator|(Head head, Tail&& tail)
 /**
  * See the documentation for boost::asio::deferred_t for a usage example.
  */
-constexpr deferred_t deferred;
+BOOST_ASIO_INLINE_VARIABLE constexpr deferred_t deferred;
 
 } // namespace asio
 } // namespace boost
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detached.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detached.hpp
index 82062e942e..d0dfce729d 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detached.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detached.hpp
@@ -39,7 +39,7 @@ namespace asio {
 class detached_t
 {
 public:
-  /// Constructor. 
+  /// Constructor.
   constexpr detached_t()
   {
   }
@@ -95,7 +95,7 @@ class detached_t
 /**
  * See the documentation for boost::asio::detached_t for a usage example.
  */
-constexpr detached_t detached;
+BOOST_ASIO_INLINE_VARIABLE constexpr detached_t detached;
 
 } // namespace asio
 } // namespace boost
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/buffered_stream_storage.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/buffered_stream_storage.hpp
index e828232deb..096efc82f8 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/buffered_stream_storage.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/buffered_stream_storage.hpp
@@ -114,7 +114,7 @@ class buffered_stream_storage
 
   // The offset to the end of the unread data.
   size_type end_offset_;
-  
+
   // The data in the buffer.
   std::vector<byte_type> buffer_;
 };
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_message.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/completion_message.hpp
similarity index 79%
rename from src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_message.hpp
rename to src/cxx_supportlib/vendor-modified/boost/asio/detail/completion_message.hpp
index c3a7b13182..345deb2106 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_message.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/completion_message.hpp
@@ -1,6 +1,6 @@
 //
-// experimental/detail/channel_message.hpp
-// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// detail/completion_message.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~
 //
 // Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
 //
@@ -8,8 +8,8 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BOOST_ASIO_EXPERIMENTAL_DETAIL_CHANNEL_MESSAGE_HPP
-#define BOOST_ASIO_EXPERIMENTAL_DETAIL_CHANNEL_MESSAGE_HPP
+#ifndef BOOST_ASIO_DETAIL_COMPLETION_MESSAGE_HPP
+#define BOOST_ASIO_DETAIL_COMPLETION_MESSAGE_HPP
 
 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
 # pragma once
@@ -24,17 +24,16 @@
 
 namespace boost {
 namespace asio {
-namespace experimental {
 namespace detail {
 
 template <typename Signature>
-class channel_message;
+class completion_message;
 
 template <typename R>
-class channel_message<R()>
+class completion_message<R()>
 {
 public:
-  channel_message(int)
+  completion_message(int)
   {
   }
 
@@ -46,11 +45,11 @@ class channel_message<R()>
 };
 
 template <typename R, typename Arg0>
-class channel_message<R(Arg0)>
+class completion_message<R(Arg0)>
 {
 public:
   template <typename T0>
-  channel_message(int, T0&& t0)
+  completion_message(int, T0&& t0)
     : arg0_(static_cast<T0&&>(t0))
   {
   }
@@ -68,11 +67,11 @@ class channel_message<R(Arg0)>
 };
 
 template <typename R, typename Arg0, typename Arg1>
-class channel_message<R(Arg0, Arg1)>
+class completion_message<R(Arg0, Arg1)>
 {
 public:
   template <typename T0, typename T1>
-  channel_message(int, T0&& t0, T1&& t1)
+  completion_message(int, T0&& t0, T1&& t1)
     : arg0_(static_cast<T0&&>(t0)),
       arg1_(static_cast<T1&&>(t1))
   {
@@ -94,11 +93,11 @@ class channel_message<R(Arg0, Arg1)>
 };
 
 template <typename R, typename... Args>
-class channel_message<R(Args...)>
+class completion_message<R(Args...)>
 {
 public:
   template <typename... T>
-  channel_message(int, T&&... t)
+  completion_message(int, T&&... t)
     : args_(static_cast<T&&>(t)...)
   {
   }
@@ -122,10 +121,9 @@ class channel_message<R(Args...)>
 };
 
 } // namespace detail
-} // namespace experimental
 } // namespace asio
 } // namespace boost
 
 #include <boost/asio/detail/pop_options.hpp>
 
-#endif // BOOST_ASIO_EXPERIMENTAL_DETAIL_CHANNEL_MESSAGE_HPP
+#endif // BOOST_ASIO_DETAIL_COMPLETION_MESSAGE_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_payload.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/completion_payload.hpp
similarity index 69%
rename from src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_payload.hpp
rename to src/cxx_supportlib/vendor-modified/boost/asio/detail/completion_payload.hpp
index 544c3d154e..1135bff3fe 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_payload.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/completion_payload.hpp
@@ -1,6 +1,6 @@
 //
-// experimental/detail/channel_payload.hpp
-// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// detail/completion_payload.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 //
 // Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
 //
@@ -8,8 +8,8 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BOOST_ASIO_EXPERIMENTAL_DETAIL_CHANNEL_PAYLOAD_HPP
-#define BOOST_ASIO_EXPERIMENTAL_DETAIL_CHANNEL_PAYLOAD_HPP
+#ifndef BOOST_ASIO_DETAIL_COMPLETION_PAYLOAD_HPP
+#define BOOST_ASIO_DETAIL_COMPLETION_PAYLOAD_HPP
 
 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
 # pragma once
@@ -18,7 +18,7 @@
 #include <boost/asio/detail/config.hpp>
 #include <boost/asio/detail/type_traits.hpp>
 #include <boost/system/error_code.hpp>
-#include <boost/asio/experimental/detail/channel_message.hpp>
+#include <boost/asio/detail/completion_message.hpp>
 
 #if defined(BOOST_ASIO_HAS_STD_VARIANT)
 # include <variant>
@@ -30,17 +30,16 @@
 
 namespace boost {
 namespace asio {
-namespace experimental {
 namespace detail {
 
 template <typename... Signatures>
-class channel_payload;
+class completion_payload;
 
 template <typename R>
-class channel_payload<R()>
+class completion_payload<R()>
 {
 public:
-  explicit channel_payload(channel_message<R()>)
+  explicit completion_payload(completion_message<R()>)
   {
   }
 
@@ -52,11 +51,11 @@ class channel_payload<R()>
 };
 
 template <typename Signature>
-class channel_payload<Signature>
+class completion_payload<Signature>
 {
 public:
-  channel_payload(channel_message<Signature>&& m)
-    : message_(static_cast<channel_message<Signature>&&>(m))
+  completion_payload(completion_message<Signature>&& m)
+    : message_(static_cast<completion_message<Signature>&&>(m))
   {
   }
 
@@ -67,18 +66,18 @@ class channel_payload<Signature>
   }
 
 private:
-  channel_message<Signature> message_;
+  completion_message<Signature> message_;
 };
 
 #if defined(BOOST_ASIO_HAS_STD_VARIANT)
 
 template <typename... Signatures>
-class channel_payload
+class completion_payload
 {
 public:
   template <typename Signature>
-  channel_payload(channel_message<Signature>&& m)
-    : message_(static_cast<channel_message<Signature>&&>(m))
+  completion_payload(completion_message<Signature>&& m)
+    : message_(static_cast<completion_message<Signature>&&>(m))
   {
   }
 
@@ -93,25 +92,25 @@ class channel_payload
   }
 
 private:
-  std::variant<channel_message<Signatures>...> message_;
+  std::variant<completion_message<Signatures>...> message_;
 };
 
 #else // defined(BOOST_ASIO_HAS_STD_VARIANT)
 
 template <typename R1, typename R2>
-class channel_payload<R1(), R2(boost::system::error_code)>
+class completion_payload<R1(), R2(boost::system::error_code)>
 {
 public:
-  typedef channel_message<R1()> void_message_type;
-  typedef channel_message<R2(boost::system::error_code)> error_message_type;
+  typedef completion_message<R1()> void_message_type;
+  typedef completion_message<R2(boost::system::error_code)> error_message_type;
 
-  channel_payload(void_message_type&&)
+  completion_payload(void_message_type&&)
     : message_(0, boost::system::error_code()),
       empty_(true)
   {
   }
 
-  channel_payload(error_message_type&& m)
+  completion_payload(error_message_type&& m)
     : message_(static_cast<error_message_type&&>(m)),
       empty_(false)
   {
@@ -121,7 +120,7 @@ class channel_payload<R1(), R2(boost::system::error_code)>
   void receive(Handler& handler)
   {
     if (empty_)
-      channel_message<R1()>(0).receive(handler);
+      completion_message<R1()>(0).receive(handler);
     else
       message_.receive(handler);
   }
@@ -132,25 +131,25 @@ class channel_payload<R1(), R2(boost::system::error_code)>
 };
 
 template <typename Sig1, typename Sig2>
-class channel_payload<Sig1, Sig2>
+class completion_payload<Sig1, Sig2>
 {
 public:
-  typedef channel_message<Sig1> message_1_type;
-  typedef channel_message<Sig2> message_2_type;
+  typedef completion_message<Sig1> message_1_type;
+  typedef completion_message<Sig2> message_2_type;
 
-  channel_payload(message_1_type&& m)
+  completion_payload(message_1_type&& m)
     : index_(1)
   {
     new (&storage_.message_1_) message_1_type(static_cast<message_1_type&&>(m));
   }
 
-  channel_payload(message_2_type&& m)
+  completion_payload(message_2_type&& m)
     : index_(2)
   {
     new (&storage_.message_2_) message_2_type(static_cast<message_2_type&&>(m));
   }
 
-  channel_payload(channel_payload&& other)
+  completion_payload(completion_payload&& other)
     : index_(other.index_)
   {
     switch (index_)
@@ -168,7 +167,7 @@ class channel_payload<Sig1, Sig2>
     }
   }
 
-  ~channel_payload()
+  ~completion_payload()
   {
     switch (index_)
     {
@@ -215,10 +214,9 @@ class channel_payload<Sig1, Sig2>
 #endif // defined(BOOST_ASIO_HAS_STD_VARIANT)
 
 } // namespace detail
-} // namespace experimental
 } // namespace asio
 } // namespace boost
 
 #include <boost/asio/detail/pop_options.hpp>
 
-#endif // BOOST_ASIO_EXPERIMENTAL_DETAIL_CHANNEL_PAYLOAD_HPP
+#endif // BOOST_ASIO_DETAIL_COMPLETION_PAYLOAD_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_handler.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/completion_payload_handler.hpp
similarity index 69%
rename from src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_handler.hpp
rename to src/cxx_supportlib/vendor-modified/boost/asio/detail/completion_payload_handler.hpp
index 09eafad233..db08b25013 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_handler.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/completion_payload_handler.hpp
@@ -1,6 +1,6 @@
 //
-// experimental/detail/channel_handler.hpp
-// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// detail/completion_payload_handler.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 //
 // Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
 //
@@ -8,8 +8,8 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BOOST_ASIO_EXPERIMENTAL_DETAIL_CHANNEL_HANDLER_HPP
-#define BOOST_ASIO_EXPERIMENTAL_DETAIL_CHANNEL_HANDLER_HPP
+#ifndef BOOST_ASIO_DETAIL_COMPLETION_PAYLOAD_HANDLER_HPP
+#define BOOST_ASIO_DETAIL_COMPLETION_PAYLOAD_HANDLER_HPP
 
 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
 # pragma once
@@ -17,20 +17,18 @@
 
 #include <boost/asio/detail/config.hpp>
 #include <boost/asio/associator.hpp>
-#include <boost/asio/experimental/detail/channel_payload.hpp>
 
 #include <boost/asio/detail/push_options.hpp>
 
 namespace boost {
 namespace asio {
-namespace experimental {
 namespace detail {
 
 template <typename Payload, typename Handler>
-class channel_handler
+class completion_payload_handler
 {
 public:
-  channel_handler(Payload&& p, Handler& h)
+  completion_payload_handler(Payload&& p, Handler& h)
     : payload_(static_cast<Payload&&>(p)),
       handler_(static_cast<Handler&&>(h))
   {
@@ -41,29 +39,33 @@ class channel_handler
     payload_.receive(handler_);
   }
 
+  Handler& handler()
+  {
+    return handler_;
+  }
+
 //private:
   Payload payload_;
   Handler handler_;
 };
 
 } // namespace detail
-} // namespace experimental
 
 template <template <typename, typename> class Associator,
     typename Payload, typename Handler, typename DefaultCandidate>
 struct associator<Associator,
-    experimental::detail::channel_handler<Payload, Handler>,
+    detail::completion_payload_handler<Payload, Handler>,
     DefaultCandidate>
   : Associator<Handler, DefaultCandidate>
 {
   static typename Associator<Handler, DefaultCandidate>::type get(
-      const experimental::detail::channel_handler<Payload, Handler>& h) noexcept
+      const detail::completion_payload_handler<Payload, Handler>& h) noexcept
   {
     return Associator<Handler, DefaultCandidate>::get(h.handler_);
   }
 
   static auto get(
-      const experimental::detail::channel_handler<Payload, Handler>& h,
+      const detail::completion_payload_handler<Payload, Handler>& h,
       const DefaultCandidate& c) noexcept
     -> decltype(Associator<Handler, DefaultCandidate>::get(h.handler_, c))
   {
@@ -76,4 +78,4 @@ struct associator<Associator,
 
 #include <boost/asio/detail/pop_options.hpp>
 
-#endif // BOOST_ASIO_EXPERIMENTAL_DETAIL_CHANNEL_HANDLER_HPP
+#endif // BOOST_ASIO_DETAIL_COMPLETION_PAYLOAD_HANDLER_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/config.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/config.hpp
index 6dd56d777e..1f02721999 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/config.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/config.hpp
@@ -127,29 +127,7 @@
 # define BOOST_ASIO_HAS_USER_DEFINED_LITERALS 1
 # define BOOST_ASIO_HAS_ALIGNOF 1
 # define BOOST_ASIO_ALIGNOF(T) alignof(T)
-// Standard library support for std::align.
-#if !defined(BOOST_ASIO_HAS_STD_ALIGN)
-# if !defined(BOOST_ASIO_DISABLE_STD_ALIGN)
-#  if defined(__clang__)
-#   if defined(BOOST_ASIO_HAS_CLANG_LIBCXX)
-#    define BOOST_ASIO_HAS_STD_ALIGN 1
-#   elif (__cplusplus >= 201103)
-#    define BOOST_ASIO_HAS_STD_ALIGN 1
-#   endif // (__cplusplus >= 201103)
-#  elif defined(__GNUC__)
-#   if (__GNUC__ >= 6)
-#    if (__cplusplus >= 201103) || defined(__GXX_EXPERIMENTAL_CXX0X__)
-#     define BOOST_ASIO_HAS_STD_ALIGN 1
-#    endif // (__cplusplus >= 201103) || defined(__GXX_EXPERIMENTAL_CXX0X__)
-#   endif // (__GNUC__ >= 6)
-#  endif // defined(__GNUC__)
-#  if defined(BOOST_ASIO_MSVC)
-#   if (_MSC_VER >= 1700)
-#    define BOOST_ASIO_HAS_STD_ALIGN 1
-#   endif // (_MSC_VER >= 1700)
-#  endif // defined(BOOST_ASIO_MSVC)
-# endif // !defined(BOOST_ASIO_DISABLE_STD_ALIGN)
-#endif // !defined(BOOST_ASIO_HAS_STD_ALIGN)
+# define BOOST_ASIO_HAS_STD_ALIGN 1
 # define BOOST_ASIO_HAS_STD_SYSTEM_ERROR 1
 # define BOOST_ASIO_ERROR_CATEGORY_NOEXCEPT noexcept(true)
 # define BOOST_ASIO_HAS_STD_ARRAY 1
@@ -363,6 +341,19 @@
 # endif // !defined(BOOST_ASIO_DISABLE_VARIADIC_LAMBDA_CAPTURES)
 #endif // !defined(BOOST_ASIO_HAS_VARIADIC_LAMBDA_CAPTURES)
 
+// Support for inline variables.
+#if !defined(BOOST_ASIO_HAS_INLINE_VARIABLES)
+# if !defined(BOOST_ASIO_DISABLE_INLINE_VARIABLES)
+#  if (__cplusplus >= 201703) && (__cpp_inline_variables >= 201606)
+#   define BOOST_ASIO_HAS_INLINE_VARIABLES 1
+#   define BOOST_ASIO_INLINE_VARIABLE inline
+#  endif // (__cplusplus >= 201703) && (__cpp_inline_variables >= 201606)
+# endif // !defined(BOOST_ASIO_DISABLE_INLINE_VARIABLES)
+#endif // !defined(BOOST_ASIO_HAS_INLINE_VARIABLES)
+#if !defined(BOOST_ASIO_INLINE_VARIABLE)
+# define BOOST_ASIO_INLINE_VARIABLE
+#endif // !defined(BOOST_ASIO_INLINE_VARIABLE)
+
 // Default alignment.
 #if defined(__STDCPP_DEFAULT_NEW_ALIGNMENT__)
 # define BOOST_ASIO_DEFAULT_ALIGN __STDCPP_DEFAULT_NEW_ALIGNMENT__
@@ -384,7 +375,9 @@
 #    if defined(BOOST_ASIO_HAS_CLANG_LIBCXX)
 #     if (_LIBCPP_STD_VER > 14) && defined(_LIBCPP_HAS_ALIGNED_ALLOC) \
         && !defined(_LIBCPP_MSVCRT) && !defined(__MINGW32__)
-#      if defined(__APPLE__)
+#      if defined(__ANDROID__) && (__ANDROID_API__ >= 28)
+#        define BOOST_ASIO_HAS_STD_ALIGNED_ALLOC 1
+#      elif defined(__APPLE__)
 #       if defined(__MAC_OS_X_VERSION_MIN_REQUIRED)
 #        if (__MAC_OS_X_VERSION_MIN_REQUIRED >= 101500)
 #         define BOOST_ASIO_HAS_STD_ALIGNED_ALLOC 1
@@ -554,9 +547,9 @@
 #    define BOOST_ASIO_HAS_STD_INVOKE_RESULT 1
 #   endif // (_MSC_VER >= 1911 && _MSVC_LANG >= 201703)
 #  else // defined(BOOST_ASIO_MSVC)
-#   if (__cplusplus >= 201703)
+#   if (__cplusplus >= 201703) && (__cpp_lib_is_invocable >= 201703)
 #    define BOOST_ASIO_HAS_STD_INVOKE_RESULT 1
-#   endif // (__cplusplus >= 201703)
+#   endif // (__cplusplus >= 201703) && (__cpp_lib_is_invocable >= 201703)
 #  endif // defined(BOOST_ASIO_MSVC)
 # endif // !defined(BOOST_ASIO_DISABLE_STD_INVOKE_RESULT)
 #endif // !defined(BOOST_ASIO_HAS_STD_INVOKE_RESULT)
@@ -1297,7 +1290,10 @@
 // Support the co_await keyword on compilers known to allow it.
 #if !defined(BOOST_ASIO_HAS_CO_AWAIT)
 # if !defined(BOOST_ASIO_DISABLE_CO_AWAIT)
-#  if defined(BOOST_ASIO_MSVC)
+#  if (__cplusplus >= 202002) \
+     && (__cpp_impl_coroutine >= 201902) && (__cpp_lib_coroutine >= 201902)
+#   define BOOST_ASIO_HAS_CO_AWAIT 1
+#  elif defined(BOOST_ASIO_MSVC)
 #   if (_MSC_VER >= 1928) && (_MSVC_LANG >= 201705) && !defined(__clang__)
 #    define BOOST_ASIO_HAS_CO_AWAIT 1
 #   elif (_MSC_FULL_VER >= 190023506)
@@ -1408,11 +1404,9 @@
 // Standard library support for snprintf.
 #if !defined(BOOST_ASIO_HAS_SNPRINTF)
 # if !defined(BOOST_ASIO_DISABLE_SNPRINTF)
-#  if defined(__apple_build_version__)
-#    if (__clang_major__ >= 14)
-#     define BOOST_ASIO_HAS_SNPRINTF 1
-#    endif // (__clang_major__ >= 14)
-#  endif // defined(__apple_build_version__)
+#  if defined(__APPLE__)
+#   define BOOST_ASIO_HAS_SNPRINTF 1
+#  endif // defined(__APPLE__)
 # endif // !defined(BOOST_ASIO_DISABLE_SNPRINTF)
 #endif // !defined(BOOST_ASIO_HAS_SNPRINTF)
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/deadline_timer_service.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/deadline_timer_service.hpp
index ee7fa97a69..72059ce725 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/deadline_timer_service.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/deadline_timer_service.hpp
@@ -104,7 +104,11 @@ class deadline_timer_service
   void move_construct(implementation_type& impl,
       implementation_type& other_impl)
   {
-    scheduler_.move_timer(timer_queue_, impl.timer_data, other_impl.timer_data);
+    if (other_impl.might_have_pending_waits)
+    {
+      scheduler_.move_timer(timer_queue_,
+          impl.timer_data, other_impl.timer_data);
+    }
 
     impl.expiry = other_impl.expiry;
     other_impl.expiry = time_type();
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/handler_alloc_helpers.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/handler_alloc_helpers.hpp
index 7b999085db..6c0a37ca35 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/handler_alloc_helpers.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/handler_alloc_helpers.hpp
@@ -17,121 +17,12 @@
 
 #include <boost/asio/detail/config.hpp>
 #include <boost/asio/detail/memory.hpp>
-#include <boost/asio/detail/noncopyable.hpp>
 #include <boost/asio/detail/recycling_allocator.hpp>
-#include <boost/asio/detail/thread_info_base.hpp>
 #include <boost/asio/associated_allocator.hpp>
 
 #include <boost/asio/detail/push_options.hpp>
 
-namespace boost {
-namespace asio {
-namespace detail {
-
-inline void* default_allocate(std::size_t s,
-    std::size_t align = BOOST_ASIO_DEFAULT_ALIGN)
-{
-#if !defined(BOOST_ASIO_DISABLE_SMALL_BLOCK_RECYCLING)
-  return boost::asio::detail::thread_info_base::allocate(
-      boost::asio::detail::thread_context::top_of_thread_call_stack(),
-      s, align);
-#else // !defined(BOOST_ASIO_DISABLE_SMALL_BLOCK_RECYCLING)
-  return boost::asio::aligned_new(align, s);
-#endif // !defined(BOOST_ASIO_DISABLE_SMALL_BLOCK_RECYCLING)
-}
-
-inline void default_deallocate(void* p, std::size_t s)
-{
-#if !defined(BOOST_ASIO_DISABLE_SMALL_BLOCK_RECYCLING)
-  boost::asio::detail::thread_info_base::deallocate(
-      boost::asio::detail::thread_context::top_of_thread_call_stack(), p, s);
-#else // !defined(BOOST_ASIO_DISABLE_SMALL_BLOCK_RECYCLING)
-  (void)s;
-  boost::asio::aligned_delete(p);
-#endif // !defined(BOOST_ASIO_DISABLE_SMALL_BLOCK_RECYCLING)
-}
-
-template <typename T>
-class default_allocator
-{
-public:
-  typedef T value_type;
-
-  template <typename U>
-  struct rebind
-  {
-    typedef default_allocator<U> other;
-  };
-
-  default_allocator() noexcept
-  {
-  }
-
-  template <typename U>
-  default_allocator(const default_allocator<U>&) noexcept
-  {
-  }
-
-  T* allocate(std::size_t n)
-  {
-    return static_cast<T*>(default_allocate(sizeof(T) * n, alignof(T)));
-  }
-
-  void deallocate(T* p, std::size_t n)
-  {
-    default_deallocate(p, sizeof(T) * n);
-  }
-};
-
-template <>
-class default_allocator<void>
-{
-public:
-  typedef void value_type;
-
-  template <typename U>
-  struct rebind
-  {
-    typedef default_allocator<U> other;
-  };
-
-  default_allocator() noexcept
-  {
-  }
-
-  template <typename U>
-  default_allocator(const default_allocator<U>&) noexcept
-  {
-  }
-};
-
-template <typename Allocator>
-struct get_default_allocator
-{
-  typedef Allocator type;
-
-  static type get(const Allocator& a)
-  {
-    return a;
-  }
-};
-
-template <typename T>
-struct get_default_allocator<std::allocator<T>>
-{
-  typedef default_allocator<T> type;
-
-  static type get(const std::allocator<T>&)
-  {
-    return type();
-  }
-};
-
-} // namespace detail
-} // namespace asio
-} // namespace boost
-
-#define BOOST_ASIO_DEFINE_HANDLER_PTR(op) \
+#define BOOST_ASIO_DEFINE_TAGGED_HANDLER_PTR(purpose, op) \
   struct ptr \
   { \
     Handler* h; \
@@ -145,11 +36,11 @@ struct get_default_allocator<std::allocator<T>>
     { \
       typedef typename ::boost::asio::associated_allocator< \
         Handler>::type associated_allocator_type; \
-      typedef typename ::boost::asio::detail::get_default_allocator< \
-        associated_allocator_type>::type default_allocator_type; \
+      typedef typename ::boost::asio::detail::get_recycling_allocator< \
+        associated_allocator_type, purpose>::type default_allocator_type; \
       BOOST_ASIO_REBIND_ALLOC(default_allocator_type, op) a( \
-            ::boost::asio::detail::get_default_allocator< \
-              associated_allocator_type>::get( \
+            ::boost::asio::detail::get_recycling_allocator< \
+              associated_allocator_type, purpose>::get( \
                 ::boost::asio::get_associated_allocator(handler))); \
       return a.allocate(1); \
     } \
@@ -164,11 +55,11 @@ struct get_default_allocator<std::allocator<T>>
       { \
         typedef typename ::boost::asio::associated_allocator< \
           Handler>::type associated_allocator_type; \
-        typedef typename ::boost::asio::detail::get_default_allocator< \
-          associated_allocator_type>::type default_allocator_type; \
+        typedef typename ::boost::asio::detail::get_recycling_allocator< \
+          associated_allocator_type, purpose>::type default_allocator_type; \
         BOOST_ASIO_REBIND_ALLOC(default_allocator_type, op) a( \
-              ::boost::asio::detail::get_default_allocator< \
-                associated_allocator_type>::get( \
+              ::boost::asio::detail::get_recycling_allocator< \
+                associated_allocator_type, purpose>::get( \
                   ::boost::asio::get_associated_allocator(*h))); \
         a.deallocate(static_cast<op*>(v), 1); \
         v = 0; \
@@ -177,6 +68,11 @@ struct get_default_allocator<std::allocator<T>>
   } \
   /**/
 
+#define BOOST_ASIO_DEFINE_HANDLER_PTR(op) \
+  BOOST_ASIO_DEFINE_TAGGED_HANDLER_PTR( \
+      ::boost::asio::detail::thread_info_base::default_tag, op ) \
+  /**/
+
 #define BOOST_ASIO_DEFINE_TAGGED_HANDLER_ALLOCATOR_PTR(purpose, op) \
   struct ptr \
   { \
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/descriptor_ops.ipp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/descriptor_ops.ipp
index 204fe60005..b60835bc0c 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/descriptor_ops.ipp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/descriptor_ops.ipp
@@ -70,25 +70,24 @@ int close(int d, state_type& state, boost::system::error_code& ec)
         ::fcntl(d, F_SETFL, flags & ~O_NONBLOCK);
 #else // defined(__SYMBIAN32__) || defined(__EMSCRIPTEN__)
       ioctl_arg_type arg = 0;
-# if defined(ENOTTY) || defined(ENOTCAPABLE)
-      result = ::ioctl(d, FIONBIO, &arg);
-      get_last_error(ec, result < 0);
-      if (false
-#  if defined(ENOTTY)
+      if ((state & possible_dup) == 0)
+      {
+        result = ::ioctl(d, FIONBIO, &arg);
+        get_last_error(ec, result < 0);
+      }
+      if ((state & possible_dup) != 0
+# if defined(ENOTTY)
           || ec.value() == ENOTTY
-#  endif // defined(ENOTTY)
-#  if defined(ENOTCAPABLE)
+# endif // defined(ENOTTY)
+# if defined(ENOTCAPABLE)
           || ec.value() == ENOTCAPABLE
-#  endif // defined(ENOTCAPABLE)
+# endif // defined(ENOTCAPABLE)
         )
       {
         int flags = ::fcntl(d, F_GETFL, 0);
         if (flags >= 0)
           ::fcntl(d, F_SETFL, flags & ~O_NONBLOCK);
       }
-# else // defined(ENOTTY) || defined(ENOTCAPABLE)
-      ::ioctl(d, FIONBIO, &arg);
-# endif // defined(ENOTTY) || defined(ENOTCAPABLE)
 #endif // defined(__SYMBIAN32__) || defined(__EMSCRIPTEN__)
       state &= ~non_blocking;
 
@@ -115,21 +114,24 @@ bool set_user_non_blocking(int d, state_type& state,
   if (result >= 0)
   {
     int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK));
-    result = ::fcntl(d, F_SETFL, flag);
+    result = (flag != result) ? ::fcntl(d, F_SETFL, flag) : 0;
     get_last_error(ec, result < 0);
   }
 #else // defined(__SYMBIAN32__) || defined(__EMSCRIPTEN__)
   ioctl_arg_type arg = (value ? 1 : 0);
-  int result = ::ioctl(d, FIONBIO, &arg);
-  get_last_error(ec, result < 0);
-# if defined(ENOTTY) || defined(ENOTCAPABLE)
-  if (false
-#  if defined(ENOTTY)
+  int result = 0;
+  if ((state & possible_dup) == 0)
+  {
+    result = ::ioctl(d, FIONBIO, &arg);
+    get_last_error(ec, result < 0);
+  }
+  if ((state & possible_dup) != 0
+# if defined(ENOTTY)
       || ec.value() == ENOTTY
-#  endif // defined(ENOTTY)
-#  if defined(ENOTCAPABLE)
+# endif // defined(ENOTTY)
+# if defined(ENOTCAPABLE)
       || ec.value() == ENOTCAPABLE
-#  endif // defined(ENOTCAPABLE)
+# endif // defined(ENOTCAPABLE)
     )
   {
     result = ::fcntl(d, F_GETFL, 0);
@@ -137,11 +139,10 @@ bool set_user_non_blocking(int d, state_type& state,
     if (result >= 0)
     {
       int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK));
-      result = ::fcntl(d, F_SETFL, flag);
+      result = (flag != result) ? ::fcntl(d, F_SETFL, flag) : 0;
       get_last_error(ec, result < 0);
     }
   }
-# endif // defined(ENOTTY) || defined(ENOTCAPABLE)
 #endif // defined(__SYMBIAN32__) || defined(__EMSCRIPTEN__)
 
   if (result >= 0)
@@ -185,21 +186,24 @@ bool set_internal_non_blocking(int d, state_type& state,
   if (result >= 0)
   {
     int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK));
-    result = ::fcntl(d, F_SETFL, flag);
+    result = (flag != result) ? ::fcntl(d, F_SETFL, flag) : 0;
     get_last_error(ec, result < 0);
   }
 #else // defined(__SYMBIAN32__) || defined(__EMSCRIPTEN__)
   ioctl_arg_type arg = (value ? 1 : 0);
-  int result = ::ioctl(d, FIONBIO, &arg);
-  get_last_error(ec, result < 0);
-# if defined(ENOTTY) || defined(ENOTCAPABLE)
-  if (false
-#  if defined(ENOTTY)
+  int result = 0;
+  if ((state & possible_dup) == 0)
+  {
+    result = ::ioctl(d, FIONBIO, &arg);
+    get_last_error(ec, result < 0);
+  }
+  if ((state & possible_dup) != 0
+# if defined(ENOTTY)
       || ec.value() == ENOTTY
-#  endif // defined(ENOTTY)
-#  if defined(ENOTCAPABLE)
+# endif // defined(ENOTTY)
+# if defined(ENOTCAPABLE)
       || ec.value() == ENOTCAPABLE
-#  endif // defined(ENOTCAPABLE)
+# endif // defined(ENOTCAPABLE)
     )
   {
     result = ::fcntl(d, F_GETFL, 0);
@@ -207,11 +211,10 @@ bool set_internal_non_blocking(int d, state_type& state,
     if (result >= 0)
     {
       int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK));
-      result = ::fcntl(d, F_SETFL, flag);
+      result = (flag != result) ? ::fcntl(d, F_SETFL, flag) : 0;
       get_last_error(ec, result < 0);
     }
   }
-# endif // defined(ENOTTY) || defined(ENOTCAPABLE)
 #endif // defined(__SYMBIAN32__) || defined(__EMSCRIPTEN__)
 
   if (result >= 0)
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/dev_poll_reactor.ipp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/dev_poll_reactor.ipp
index 30647d6d40..e50f696d48 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/dev_poll_reactor.ipp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/dev_poll_reactor.ipp
@@ -67,7 +67,7 @@ void dev_poll_reactor::shutdown()
   timer_queues_.get_all_timers(ops);
 
   scheduler_.abandon_operations(ops);
-} 
+}
 
 void dev_poll_reactor::notify_fork(
     boost::asio::execution_context::fork_event fork_ev)
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/reactive_descriptor_service.ipp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/reactive_descriptor_service.ipp
index 292c60de7b..858a135b38 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/reactive_descriptor_service.ipp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/reactive_descriptor_service.ipp
@@ -199,18 +199,20 @@ boost::system::error_code reactive_descriptor_service::cancel(
 }
 
 void reactive_descriptor_service::do_start_op(implementation_type& impl,
-    int op_type, reactor_op* op, bool is_continuation, bool is_non_blocking,
-    bool noop, void (*on_immediate)(operation* op, bool, const void*),
+    int op_type, reactor_op* op, bool is_continuation,
+    bool allow_speculative, bool noop, bool needs_non_blocking,
+    void (*on_immediate)(operation* op, bool, const void*),
     const void* immediate_arg)
 {
   if (!noop)
   {
-    if ((impl.state_ & descriptor_ops::non_blocking) ||
-        descriptor_ops::set_internal_non_blocking(
+    if ((impl.state_ & descriptor_ops::non_blocking)
+        || !needs_non_blocking
+        || descriptor_ops::set_internal_non_blocking(
           impl.descriptor_, impl.state_, true, op->ec_))
     {
       reactor_.start_op(op_type, impl.descriptor_, impl.reactor_data_, op,
-          is_continuation, is_non_blocking, on_immediate, immediate_arg);
+          is_continuation, allow_speculative, on_immediate, immediate_arg);
       return;
     }
   }
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/reactive_socket_service_base.ipp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/reactive_socket_service_base.ipp
index 6cf1197eae..22f6ba3a6d 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/reactive_socket_service_base.ipp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/reactive_socket_service_base.ipp
@@ -235,19 +235,21 @@ boost::system::error_code reactive_socket_service_base::do_assign(
 }
 
 void reactive_socket_service_base::do_start_op(
-    reactive_socket_service_base::base_implementation_type& impl, int op_type,
-    reactor_op* op, bool is_continuation, bool is_non_blocking, bool noop,
+    reactive_socket_service_base::base_implementation_type& impl,
+    int op_type, reactor_op* op, bool is_continuation,
+    bool allow_speculative, bool noop, bool needs_non_blocking,
     void (*on_immediate)(operation* op, bool, const void*),
     const void* immediate_arg)
 {
   if (!noop)
   {
     if ((impl.state_ & socket_ops::non_blocking)
+        || !needs_non_blocking
         || socket_ops::set_internal_non_blocking(
           impl.socket_, impl.state_, true, op->ec_))
     {
       reactor_.start_op(op_type, impl.socket_, impl.reactor_data_, op,
-          is_continuation, is_non_blocking, on_immediate, immediate_arg);
+          is_continuation, allow_speculative, on_immediate, immediate_arg);
       return;
     }
   }
@@ -264,7 +266,7 @@ void reactive_socket_service_base::do_start_accept_op(
   if (!peer_is_open)
   {
     do_start_op(impl, reactor::read_op, op, is_continuation,
-        true, false, on_immediate, immediate_arg);
+        true, false, true, on_immediate, immediate_arg);
   }
   else
   {
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/socket_ops.ipp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/socket_ops.ipp
index 74b4ecc770..2548c2987d 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/socket_ops.ipp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/socket_ops.ipp
@@ -41,6 +41,10 @@
 #endif // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
        // || defined(__MACH__) && defined(__APPLE__)
 
+#if defined(_MSC_VER) && (_MSC_VER >= 1800)
+# include <malloc.h>
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1800)
+
 #include <boost/asio/detail/push_options.hpp>
 
 namespace boost {
@@ -340,25 +344,24 @@ int close(socket_type s, state_type& state,
         ::fcntl(s, F_SETFL, flags & ~O_NONBLOCK);
 # else // defined(__SYMBIAN32__) || defined(__EMSCRIPTEN__)
       ioctl_arg_type arg = 0;
-#  if defined(ENOTTY) || defined(ENOTCAPABLE)
-      result = ::ioctl(s, FIONBIO, &arg);
-      get_last_error(ec, result < 0);
-      if (false
-#   if defined(ENOTTY)
+      if ((state & possible_dup) == 0)
+      {
+        result = ::ioctl(s, FIONBIO, &arg);
+        get_last_error(ec, result < 0);
+      }
+      if ((state & possible_dup) != 0
+#  if defined(ENOTTY)
           || ec.value() == ENOTTY
-#   endif // defined(ENOTTY)
-#   if defined(ENOTCAPABLE)
+#  endif // defined(ENOTTY)
+#  if defined(ENOTCAPABLE)
           || ec.value() == ENOTCAPABLE
-#   endif // defined(ENOTCAPABLE)
+#  endif // defined(ENOTCAPABLE)
         )
       {
         int flags = ::fcntl(s, F_GETFL, 0);
         if (flags >= 0)
           ::fcntl(s, F_SETFL, flags & ~O_NONBLOCK);
       }
-#  else // defined(ENOTTY) || defined(ENOTCAPABLE)
-      ::ioctl(s, FIONBIO, &arg);
-#  endif // defined(ENOTTY) || defined(ENOTCAPABLE)
 # endif // defined(__SYMBIAN32__) || defined(__EMSCRIPTEN__)
 #endif // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
       state &= ~non_blocking;
@@ -394,21 +397,24 @@ bool set_user_non_blocking(socket_type s,
   if (result >= 0)
   {
     int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK));
-    result = ::fcntl(s, F_SETFL, flag);
+    result = (flag != result) ? ::fcntl(s, F_SETFL, flag) : 0;
     get_last_error(ec, result < 0);
   }
 #else // defined(__SYMBIAN32__) || defined(__EMSCRIPTEN__)
   ioctl_arg_type arg = (value ? 1 : 0);
-  int result = ::ioctl(s, FIONBIO, &arg);
-  get_last_error(ec, result < 0);
-# if defined(ENOTTY) || defined(ENOTCAPABLE)
-  if (false
-#  if defined(ENOTTY)
+  int result = 0;
+  if ((state & possible_dup) == 0)
+  {
+    result = ::ioctl(s, FIONBIO, &arg);
+    get_last_error(ec, result < 0);
+  }
+  if ((state & possible_dup) != 0
+# if defined(ENOTTY)
       || ec.value() == ENOTTY
-#  endif // defined(ENOTTY)
-#  if defined(ENOTCAPABLE)
+# endif // defined(ENOTTY)
+# if defined(ENOTCAPABLE)
       || ec.value() == ENOTCAPABLE
-#  endif // defined(ENOTCAPABLE)
+# endif // defined(ENOTCAPABLE)
     )
   {
     result = ::fcntl(s, F_GETFL, 0);
@@ -416,11 +422,10 @@ bool set_user_non_blocking(socket_type s,
     if (result >= 0)
     {
       int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK));
-      result = ::fcntl(s, F_SETFL, flag);
+      result = (flag != result) ? ::fcntl(s, F_SETFL, flag) : 0;
       get_last_error(ec, result < 0);
     }
   }
-# endif // defined(ENOTTY) || defined(ENOTCAPABLE)
 #endif // defined(__SYMBIAN32__) || defined(__EMSCRIPTEN__)
 
   if (result >= 0)
@@ -468,21 +473,24 @@ bool set_internal_non_blocking(socket_type s,
   if (result >= 0)
   {
     int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK));
-    result = ::fcntl(s, F_SETFL, flag);
+    result = (flag != result) ? ::fcntl(s, F_SETFL, flag) : 0;
     get_last_error(ec, result < 0);
   }
 #else // defined(__SYMBIAN32__) || defined(__EMSCRIPTEN__)
   ioctl_arg_type arg = (value ? 1 : 0);
-  int result = ::ioctl(s, FIONBIO, &arg);
-  get_last_error(ec, result < 0);
-# if defined(ENOTTY) || defined(ENOTCAPABLE)
-  if (false
-#  if defined(ENOTTY)
+  int result = 0;
+  if ((state & possible_dup) == 0)
+  {
+    result = ::ioctl(s, FIONBIO, &arg);
+    get_last_error(ec, result < 0);
+  }
+  if ((state & possible_dup) != 0
+# if defined(ENOTTY)
       || ec.value() == ENOTTY
-#  endif // defined(ENOTTY)
-#  if defined(ENOTCAPABLE)
+# endif // defined(ENOTTY)
+# if defined(ENOTCAPABLE)
       || ec.value() == ENOTCAPABLE
-#  endif // defined(ENOTCAPABLE)
+# endif // defined(ENOTCAPABLE)
     )
   {
     result = ::fcntl(s, F_GETFL, 0);
@@ -490,11 +498,10 @@ bool set_internal_non_blocking(socket_type s,
     if (result >= 0)
     {
       int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK));
-      result = ::fcntl(s, F_SETFL, flag);
+      result = (flag != result) ? ::fcntl(s, F_SETFL, flag) : 0;
       get_last_error(ec, result < 0);
     }
   }
-# endif // defined(ENOTTY) || defined(ENOTCAPABLE)
 #endif // defined(__SYMBIAN32__) || defined(__EMSCRIPTEN__)
 
   if (result >= 0)
@@ -2580,9 +2587,11 @@ const char* inet_ntop(int af, const void* src, char* dest, size_t length,
         || if_indextoname(static_cast<unsigned>(scope_id), if_name + 1) == 0)
 #if defined(BOOST_ASIO_HAS_SNPRINTF)
       snprintf(if_name + 1, sizeof(if_name) - 1, "%lu", scope_id);
-#else // defined(BOOST_ASIO_HAS_SNPRINTF)
+#elif defined(BOOST_ASIO_HAS_SECURE_RTL)
+      sprintf_s(if_name + 1, sizeof(if_name) -1, "%lu", scope_id);
+#else // defined(BOOST_ASIO_HAS_SECURE_RTL)
       sprintf(if_name + 1, "%lu", scope_id);
-#endif // defined(BOOST_ASIO_HAS_SNPRINTF)
+#endif // defined(BOOST_ASIO_HAS_SECURE_RTL)
     strcat(dest, if_name);
   }
   return result;
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/socket_select_interrupter.ipp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/socket_select_interrupter.ipp
index 58c7daad8f..cb62e14717 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/socket_select_interrupter.ipp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/impl/socket_select_interrupter.ipp
@@ -91,7 +91,7 @@ void socket_select_interrupter::open_descriptors()
   socket_holder server(socket_ops::accept(acceptor.get(), 0, 0, ec));
   if (server.get() == invalid_socket)
     boost::asio::detail::throw_error(ec, "socket_select_interrupter");
-  
+
   ioctl_arg_type non_blocking = 1;
   socket_ops::state_type client_state = 0;
   if (socket_ops::ioctl(client.get(), client_state,
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/initiation_base.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/initiation_base.hpp
new file mode 100644
index 0000000000..9c1597b24e
--- /dev/null
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/initiation_base.hpp
@@ -0,0 +1,64 @@
+//
+// detail/initiation_base.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_INITIATION_BASE_HPP
+#define BOOST_ASIO_DETAIL_INITIATION_BASE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/detail/type_traits.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename Initiation, typename = void>
+class initiation_base : public Initiation
+{
+public:
+  template <typename I>
+  explicit initiation_base(I&& initiation)
+    : Initiation(static_cast<I&&>(initiation))
+  {
+  }
+};
+
+template <typename Initiation>
+class initiation_base<Initiation, enable_if_t<!is_class<Initiation>::value>>
+{
+public:
+  template <typename I>
+  explicit initiation_base(I&& initiation)
+    : initiation_(static_cast<I&&>(initiation))
+  {
+  }
+
+  template <typename... Args>
+  void operator()(Args&&... args) const
+  {
+    initiation_(static_cast<Args&&>(args)...);
+  }
+
+private:
+  Initiation initiation_;
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_DETAIL_INITIATION_BASE_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/memory.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/memory.hpp
index c183fe991c..4d8822429b 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/memory.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/memory.hpp
@@ -55,18 +55,7 @@ inline const volatile T* to_address(const volatile T* p) { return p; }
 inline void* align(std::size_t alignment,
     std::size_t size, void*& ptr, std::size_t& space)
 {
-#if defined(BOOST_ASIO_HAS_STD_ALIGN)
   return std::align(alignment, size, ptr, space);
-#else // defined(BOOST_ASIO_HAS_STD_ALIGN)
-	const uintptr_t intptr = reinterpret_cast<uintptr_t>(ptr);
-	const uintptr_t aligned = (intptr - 1u + alignment) & -alignment;
-	const std::size_t padding = aligned - intptr;
-	if (size + padding > space)
-    return 0;
-	space -= padding;
-	ptr = reinterpret_cast<void*>(aligned);
-  return ptr;
-#endif // defined(BOOST_ASIO_HAS_STD_ALIGN)
 }
 
 } // namespace detail
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_descriptor_service.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_descriptor_service.hpp
index 8af1a038bf..301c7c478b 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_descriptor_service.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_descriptor_service.hpp
@@ -240,7 +240,7 @@ class reactive_descriptor_service :
     default:
       p.p->ec_ = boost::asio::error::invalid_argument;
       start_op(impl, reactor::read_op, p.p,
-          is_continuation, false, true, &io_ex, 0);
+          is_continuation, false, true, false, &io_ex, 0);
       p.v = p.p = 0;
       return;
     }
@@ -253,7 +253,8 @@ class reactive_descriptor_service :
             &reactor_, &impl.reactor_data_, impl.descriptor_, op_type);
     }
 
-    start_op(impl, op_type, p.p, is_continuation, false, false, &io_ex, 0);
+    start_op(impl, op_type, p.p, is_continuation,
+        false, false, false, &io_ex, 0);
     p.v = p.p = 0;
   }
 
@@ -327,7 +328,7 @@ class reactive_descriptor_service :
 
     start_op(impl, reactor::write_op, p.p, is_continuation, true,
         buffer_sequence_adapter<boost::asio::const_buffer,
-          ConstBufferSequence>::all_empty(buffers), &io_ex, 0);
+          ConstBufferSequence>::all_empty(buffers), true, &io_ex, 0);
     p.v = p.p = 0;
   }
 
@@ -361,7 +362,7 @@ class reactive_descriptor_service :
           &impl, impl.descriptor_, "async_write_some(null_buffers)"));
 
     start_op(impl, reactor::write_op, p.p,
-        is_continuation, false, false, &io_ex, 0);
+        is_continuation, false, false, false, &io_ex, 0);
     p.v = p.p = 0;
   }
 
@@ -436,7 +437,7 @@ class reactive_descriptor_service :
 
     start_op(impl, reactor::read_op, p.p, is_continuation, true,
         buffer_sequence_adapter<boost::asio::mutable_buffer,
-          MutableBufferSequence>::all_empty(buffers), &io_ex, 0);
+          MutableBufferSequence>::all_empty(buffers), true, &io_ex, 0);
     p.v = p.p = 0;
   }
 
@@ -470,14 +471,15 @@ class reactive_descriptor_service :
           &impl, impl.descriptor_, "async_read_some(null_buffers)"));
 
     start_op(impl, reactor::read_op, p.p,
-        is_continuation, false, false, &io_ex, 0);
+        is_continuation, false, false, false, &io_ex, 0);
     p.v = p.p = 0;
   }
 
 private:
   // Start the asynchronous operation.
-  BOOST_ASIO_DECL void do_start_op(implementation_type& impl, int op_type,
-      reactor_op* op, bool is_continuation, bool is_non_blocking, bool noop,
+  BOOST_ASIO_DECL void do_start_op(implementation_type& impl,
+      int op_type, reactor_op* op, bool is_continuation,
+      bool allow_speculative, bool noop, bool needs_non_blocking,
       void (*on_immediate)(operation* op, bool, const void*),
       const void* immediate_arg);
 
@@ -485,18 +487,19 @@ class reactive_descriptor_service :
   // immediate completion.
   template <typename Op>
   void start_op(implementation_type& impl, int op_type, Op* op,
-      bool is_continuation, bool is_non_blocking, bool noop,
-      const void* io_ex, ...)
+      bool is_continuation, bool allow_speculative, bool noop,
+      bool needs_non_blocking, const void* io_ex, ...)
   {
-    return do_start_op(impl, op_type, op, is_continuation,
-        is_non_blocking, noop, &Op::do_immediate, io_ex);
+    return do_start_op(impl, op_type, op, is_continuation, allow_speculative,
+        noop, needs_non_blocking, &Op::do_immediate, io_ex);
   }
 
   // Start the asynchronous operation for handlers that are not specialised for
   // immediate completion.
   template <typename Op>
-  void start_op(implementation_type& impl, int op_type, Op* op,
-      bool is_continuation, bool is_non_blocking, bool noop, const void*,
+  void start_op(implementation_type& impl, int op_type,
+      Op* op, bool is_continuation, bool allow_speculative,
+      bool noop, bool needs_non_blocking, const void*,
       enable_if_t<
         is_same<
           typename associated_immediate_executor<
@@ -507,8 +510,9 @@ class reactive_descriptor_service :
         >::value
       >*)
   {
-    return do_start_op(impl, op_type, op, is_continuation, is_non_blocking,
-        noop, &reactor::call_post_immediate_completion, &reactor_);
+    return do_start_op(impl, op_type, op, is_continuation,
+        allow_speculative, noop, needs_non_blocking,
+        &reactor::call_post_immediate_completion, &reactor_);
   }
 
   // Helper class used to implement per-operation cancellation
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_socket_send_op.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_socket_send_op.hpp
index 778c811c1d..09740564aa 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_socket_send_op.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_socket_send_op.hpp
@@ -188,7 +188,6 @@ class reactive_socket_send_op :
     BOOST_ASIO_HANDLER_INVOCATION_END;
   }
 
-
 private:
   Handler handler_;
   handler_work<Handler, IoExecutor> work_;
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_socket_service.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_socket_service.hpp
index ff051f979e..85e92e6b4f 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_socket_service.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_socket_service.hpp
@@ -308,7 +308,7 @@ class reactive_socket_service :
           &impl, impl.socket_, "async_send_to"));
 
     start_op(impl, reactor::write_op, p.p,
-        is_continuation, true, false, &io_ex, 0);
+        is_continuation, true, false, true, &io_ex, 0);
     p.v = p.p = 0;
   }
 
@@ -342,7 +342,7 @@ class reactive_socket_service :
           &impl, impl.socket_, "async_send_to(null_buffers)"));
 
     start_op(impl, reactor::write_op, p.p,
-        is_continuation, false, false, &io_ex, 0);
+        is_continuation, false, false, false, &io_ex, 0);
     p.v = p.p = 0;
   }
 
@@ -433,7 +433,7 @@ class reactive_socket_service :
     start_op(impl,
         (flags & socket_base::message_out_of_band)
           ? reactor::except_op : reactor::read_op,
-        p.p, is_continuation, true, false, &io_ex, 0);
+        p.p, is_continuation, true, false, true, &io_ex, 0);
     p.v = p.p = 0;
   }
 
@@ -472,7 +472,7 @@ class reactive_socket_service :
     start_op(impl,
         (flags & socket_base::message_out_of_band)
           ? reactor::except_op : reactor::read_op,
-        p.p, is_continuation, false, false, &io_ex, 0);
+        p.p, is_continuation, false, false, false, &io_ex, 0);
     p.v = p.p = 0;
   }
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_socket_service_base.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_socket_service_base.hpp
index e2d92190fd..0de10a94de 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_socket_service_base.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/reactive_socket_service_base.hpp
@@ -230,7 +230,7 @@ class reactive_socket_service_base
     default:
       p.p->ec_ = boost::asio::error::invalid_argument;
       start_op(impl, reactor::read_op, p.p,
-          is_continuation, false, true, &io_ex, 0);
+          is_continuation, false, true, false, &io_ex, 0);
       p.v = p.p = 0;
       return;
     }
@@ -243,7 +243,8 @@ class reactive_socket_service_base
             &reactor_, &impl.reactor_data_, impl.socket_, op_type);
     }
 
-    start_op(impl, op_type, p.p, is_continuation, false, false, &io_ex, 0);
+    start_op(impl, op_type, p.p, is_continuation,
+        false, false, false, &io_ex, 0);
     p.v = p.p = 0;
   }
 
@@ -315,7 +316,7 @@ class reactive_socket_service_base
     start_op(impl, reactor::write_op, p.p, is_continuation, true,
         ((impl.state_ & socket_ops::stream_oriented)
           && buffer_sequence_adapter<boost::asio::const_buffer,
-            ConstBufferSequence>::all_empty(buffers)), &io_ex, 0);
+            ConstBufferSequence>::all_empty(buffers)), true, &io_ex, 0);
     p.v = p.p = 0;
   }
 
@@ -348,7 +349,7 @@ class reactive_socket_service_base
           &impl, impl.socket_, "async_send(null_buffers)"));
 
     start_op(impl, reactor::write_op, p.p,
-        is_continuation, false, false, &io_ex, 0);
+        is_continuation, false, false, false, &io_ex, 0);
     p.v = p.p = 0;
   }
 
@@ -425,7 +426,7 @@ class reactive_socket_service_base
         (flags & socket_base::message_out_of_band) == 0,
         ((impl.state_ & socket_ops::stream_oriented)
           && buffer_sequence_adapter<boost::asio::mutable_buffer,
-            MutableBufferSequence>::all_empty(buffers)), &io_ex, 0);
+            MutableBufferSequence>::all_empty(buffers)), true, &io_ex, 0);
     p.v = p.p = 0;
   }
 
@@ -461,7 +462,7 @@ class reactive_socket_service_base
     start_op(impl,
         (flags & socket_base::message_out_of_band)
           ? reactor::except_op : reactor::read_op,
-        p.p, is_continuation, false, false, &io_ex, 0);
+        p.p, is_continuation, false, false, false, &io_ex, 0);
     p.v = p.p = 0;
   }
 
@@ -533,7 +534,8 @@ class reactive_socket_service_base
         (in_flags & socket_base::message_out_of_band)
           ? reactor::except_op : reactor::read_op,
         p.p, is_continuation,
-        (in_flags & socket_base::message_out_of_band) == 0, false, &io_ex, 0);
+        (in_flags & socket_base::message_out_of_band) == 0,
+        false, true, &io_ex, 0);
     p.v = p.p = 0;
   }
 
@@ -574,7 +576,7 @@ class reactive_socket_service_base
     start_op(impl,
         (in_flags & socket_base::message_out_of_band)
           ? reactor::except_op : reactor::read_op,
-        p.p, is_continuation, false, false, &io_ex, 0);
+        p.p, is_continuation, false, false, false, &io_ex, 0);
     p.v = p.p = 0;
   }
 
@@ -590,8 +592,9 @@ class reactive_socket_service_base
       const native_handle_type& native_socket, boost::system::error_code& ec);
 
   // Start the asynchronous read or write operation.
-  BOOST_ASIO_DECL void do_start_op(base_implementation_type& impl, int op_type,
-      reactor_op* op, bool is_continuation, bool is_non_blocking, bool noop,
+  BOOST_ASIO_DECL void do_start_op(base_implementation_type& impl,
+      int op_type, reactor_op* op, bool is_continuation,
+      bool allow_speculative, bool noop, bool needs_non_blocking,
       void (*on_immediate)(operation* op, bool, const void*),
       const void* immediate_arg);
 
@@ -599,18 +602,19 @@ class reactive_socket_service_base
   // immediate completion.
   template <typename Op>
   void start_op(base_implementation_type& impl, int op_type, Op* op,
-      bool is_continuation, bool is_non_blocking, bool noop,
-      const void* io_ex, ...)
+      bool is_continuation, bool allow_speculative, bool noop,
+      bool needs_non_blocking, const void* io_ex, ...)
   {
-    return do_start_op(impl, op_type, op, is_continuation,
-        is_non_blocking, noop, &Op::do_immediate, io_ex);
+    return do_start_op(impl, op_type, op, is_continuation, allow_speculative,
+        noop, needs_non_blocking, &Op::do_immediate, io_ex);
   }
 
   // Start the asynchronous operation for handlers that are not specialised for
   // immediate completion.
   template <typename Op>
-  void start_op(base_implementation_type& impl, int op_type, Op* op,
-      bool is_continuation, bool is_non_blocking, bool noop, const void*,
+  void start_op(base_implementation_type& impl, int op_type,
+      Op* op, bool is_continuation, bool allow_speculative,
+      bool noop, bool needs_non_blocking, const void*,
       enable_if_t<
         is_same<
           typename associated_immediate_executor<
@@ -621,8 +625,9 @@ class reactive_socket_service_base
         >::value
       >*)
   {
-    return do_start_op(impl, op_type, op, is_continuation, is_non_blocking,
-        noop, &reactor::call_post_immediate_completion, &reactor_);
+    return do_start_op(impl, op_type, op, is_continuation,
+        allow_speculative, noop, needs_non_blocking,
+        &reactor::call_post_immediate_completion, &reactor_);
   }
 
   // Start the asynchronous accept operation.
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/recycling_allocator.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/recycling_allocator.hpp
index 376df6f986..6089db4abd 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/recycling_allocator.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/recycling_allocator.hpp
@@ -49,16 +49,25 @@ class recycling_allocator
 
   T* allocate(std::size_t n)
   {
+#if !defined(BOOST_ASIO_DISABLE_SMALL_BLOCK_RECYCLING)
     void* p = thread_info_base::allocate(Purpose(),
         thread_context::top_of_thread_call_stack(),
         sizeof(T) * n, alignof(T));
+#else // !defined(BOOST_ASIO_DISABLE_SMALL_BLOCK_RECYCLING)
+    void* p = boost::asio::aligned_new(align, s);
+#endif // !defined(BOOST_ASIO_DISABLE_SMALL_BLOCK_RECYCLING)
     return static_cast<T*>(p);
   }
 
   void deallocate(T* p, std::size_t n)
   {
+#if !defined(BOOST_ASIO_DISABLE_SMALL_BLOCK_RECYCLING)
     thread_info_base::deallocate(Purpose(),
         thread_context::top_of_thread_call_stack(), p, sizeof(T) * n);
+#else // !defined(BOOST_ASIO_DISABLE_SMALL_BLOCK_RECYCLING)
+    (void)n;
+    boost::asio::aligned_delete(p);
+#endif // !defined(BOOST_ASIO_DISABLE_SMALL_BLOCK_RECYCLING)
   }
 };
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/resolve_endpoint_op.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/resolve_endpoint_op.hpp
index bf2af514d5..74f19855d8 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/resolve_endpoint_op.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/resolve_endpoint_op.hpp
@@ -78,7 +78,7 @@ class resolve_endpoint_op : public resolve_op
     {
       // The operation is being run on the worker io_context. Time to perform
       // the resolver operation.
-    
+
       // Perform the blocking endpoint resolution operation.
       char host_name[NI_MAXHOST] = "";
       char service_name[NI_MAXSERV] = "";
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/resolve_query_op.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/resolve_query_op.hpp
index d5e229634e..369131da4e 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/resolve_query_op.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/resolve_query_op.hpp
@@ -86,7 +86,7 @@ class resolve_query_op : public resolve_op
     {
       // The operation is being run on the worker io_context. Time to perform
       // the resolver operation.
-    
+
       // Perform the blocking host resolution operation.
       socket_ops::background_getaddrinfo(o->cancel_token_,
           o->query_.host_name().c_str(), o->query_.service_name().c_str(),
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/thread_info_base.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/thread_info_base.hpp
index 6f33a815db..8676ccc50f 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/thread_info_base.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/thread_info_base.hpp
@@ -90,7 +90,17 @@ class thread_info_base
     };
   };
 
-  enum { max_mem_index = parallel_group_tag::end_mem_index };
+  struct timed_cancel_tag
+  {
+    enum
+    {
+      cache_size = BOOST_ASIO_RECYCLING_ALLOCATOR_CACHE_SIZE,
+      begin_mem_index = parallel_group_tag::end_mem_index,
+      end_mem_index = begin_mem_index + cache_size
+    };
+  };
+
+  enum { max_mem_index = timed_cancel_tag::end_mem_index };
 
   thread_info_base()
 #if !defined(BOOST_ASIO_NO_EXCEPTIONS)
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/timed_cancel_op.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/timed_cancel_op.hpp
new file mode 100644
index 0000000000..3464e48bc4
--- /dev/null
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/timed_cancel_op.hpp
@@ -0,0 +1,363 @@
+//
+// detail/timed_cancel_op.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_DETAIL_TIMED_CANCEL_OP_HPP
+#define BOOST_ASIO_DETAIL_TIMED_CANCEL_OP_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/associated_cancellation_slot.hpp>
+#include <boost/asio/associator.hpp>
+#include <boost/asio/basic_waitable_timer.hpp>
+#include <boost/asio/cancellation_signal.hpp>
+#include <boost/asio/detail/atomic_count.hpp>
+#include <boost/asio/detail/completion_payload.hpp>
+#include <boost/asio/detail/completion_payload_handler.hpp>
+#include <boost/asio/detail/handler_alloc_helpers.hpp>
+#include <boost/asio/detail/type_traits.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename Op, typename... Signatures>
+class timed_cancel_op_handler;
+
+template <typename Op>
+class timed_cancel_timer_handler;
+
+template <typename Handler, typename Timer, typename... Signatures>
+class timed_cancel_op
+{
+public:
+  using handler_type = Handler;
+
+  BOOST_ASIO_DEFINE_TAGGED_HANDLER_PTR(
+      thread_info_base::timed_cancel_tag, timed_cancel_op);
+
+  timed_cancel_op(Handler& handler, Timer timer,
+      cancellation_type_t cancel_type)
+    : ref_count_(2),
+      handler_(static_cast<Handler&&>(handler)),
+      timer_(static_cast<Timer&&>(timer)),
+      cancellation_type_(cancel_type),
+      cancel_proxy_(nullptr),
+      has_payload_(false),
+      has_pending_timer_wait_(true)
+  {
+  }
+
+  ~timed_cancel_op()
+  {
+    if (has_payload_)
+      payload_storage_.payload_.~payload_type();
+  }
+
+  cancellation_slot get_cancellation_slot() noexcept
+  {
+    return cancellation_signal_.slot();
+  }
+
+  template <typename Initiation, typename... Args>
+  void start(Initiation&& initiation, Args&&... args)
+  {
+    using op_handler_type =
+      timed_cancel_op_handler<timed_cancel_op, Signatures...>;
+    op_handler_type op_handler(this);
+
+    using timer_handler_type =
+      timed_cancel_timer_handler<timed_cancel_op>;
+    timer_handler_type timer_handler(this);
+
+    associated_cancellation_slot_t<Handler> slot
+      = (get_associated_cancellation_slot)(handler_);
+    if (slot.is_connected())
+      cancel_proxy_ = &slot.template emplace<cancel_proxy>(this);
+
+    timer_.async_wait(static_cast<timer_handler_type&&>(timer_handler));
+    async_initiate<op_handler_type, Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        static_cast<op_handler_type&>(op_handler),
+        static_cast<Args&&>(args)...);
+  }
+
+  template <typename Message>
+  void handle_op(Message&& message)
+  {
+    if (cancel_proxy_)
+      cancel_proxy_->op_ = nullptr;
+
+    new (&payload_storage_.payload_) payload_type(
+        static_cast<Message&&>(message));
+    has_payload_ = true;
+
+    if (has_pending_timer_wait_)
+    {
+      timer_.cancel();
+      release();
+    }
+    else
+    {
+      complete();
+    }
+  }
+
+  void handle_timer()
+  {
+    has_pending_timer_wait_ = false;
+
+    if (has_payload_)
+    {
+      complete();
+    }
+    else
+    {
+      cancellation_signal_.emit(cancellation_type_);
+      release();
+    }
+  }
+
+  void release()
+  {
+    if (--ref_count_ == 0)
+    {
+      ptr p = { boost::asio::detail::addressof(handler_), this, this };
+      Handler handler(static_cast<Handler&&>(handler_));
+      p.h = boost::asio::detail::addressof(handler);
+      p.reset();
+    }
+  }
+
+  void complete()
+  {
+    if (--ref_count_ == 0)
+    {
+      ptr p = { boost::asio::detail::addressof(handler_), this, this };
+      completion_payload_handler<payload_type, Handler> handler(
+          static_cast<payload_type&&>(payload_storage_.payload_), handler_);
+      p.h = boost::asio::detail::addressof(handler.handler());
+      p.reset();
+      handler();
+    }
+  }
+
+//private:
+  typedef completion_payload<Signatures...> payload_type;
+
+  struct cancel_proxy
+  {
+    cancel_proxy(timed_cancel_op* op)
+      : op_(op)
+    {
+    }
+
+    void operator()(cancellation_type_t type)
+    {
+      if (op_)
+        op_->cancellation_signal_.emit(type);
+    }
+
+    timed_cancel_op* op_;
+  };
+
+  // The number of handlers that share a reference to the state.
+  atomic_count ref_count_;
+
+  // The handler to be called when the operation completes.
+  Handler handler_;
+
+  // The timer used to determine when to cancel the pending operation.
+  Timer timer_;
+
+  // The cancellation signal and type used to cancel the pending operation.
+  cancellation_signal cancellation_signal_;
+  cancellation_type_t cancellation_type_;
+
+  // A proxy cancel handler used to allow cancellation of the timed operation.
+  cancel_proxy* cancel_proxy_;
+
+  // Arguments to be passed to the completion handler.
+  union payload_storage
+  {
+    payload_storage() {}
+    ~payload_storage() {}
+
+    char dummy_;
+    payload_type payload_;
+  } payload_storage_;
+
+  // Whether the payload storage contains a valid payload.
+  bool has_payload_;
+
+  // Whether the asynchronous wait on the timer is still pending
+  bool has_pending_timer_wait_;
+};
+
+template <typename Op, typename R, typename... Args>
+class timed_cancel_op_handler<Op, R(Args...)>
+{
+public:
+  using cancellation_slot_type = cancellation_slot;
+
+  explicit timed_cancel_op_handler(Op* op)
+    : op_(op)
+  {
+  }
+
+  timed_cancel_op_handler(timed_cancel_op_handler&& other) noexcept
+    : op_(other.op_)
+  {
+    other.op_ = nullptr;
+  }
+
+  ~timed_cancel_op_handler()
+  {
+    if (op_)
+      op_->release();
+  }
+
+  cancellation_slot_type get_cancellation_slot() const noexcept
+  {
+    return op_->get_cancellation_slot();
+  }
+
+  template <typename... Args2>
+  enable_if_t<
+    is_constructible<completion_message<R(Args...)>, int, Args2...>::value
+  > operator()(Args2&&... args)
+  {
+    Op* op = op_;
+    op_ = nullptr;
+    typedef completion_message<R(Args...)> message_type;
+    op->handle_op(message_type(0, static_cast<Args2&&>(args)...));
+  }
+
+//protected:
+  Op* op_;
+};
+
+template <typename Op, typename R, typename... Args, typename... Signatures>
+class timed_cancel_op_handler<Op, R(Args...), Signatures...> :
+  public timed_cancel_op_handler<Op, Signatures...>
+{
+public:
+  using timed_cancel_op_handler<Op, Signatures...>::timed_cancel_op_handler;
+  using timed_cancel_op_handler<Op, Signatures...>::operator();
+
+  template <typename... Args2>
+  enable_if_t<
+    is_constructible<completion_message<R(Args...)>, int, Args2...>::value
+  > operator()(Args2&&... args)
+  {
+    Op* op = this->op_;
+    this->op_ = nullptr;
+    typedef completion_message<R(Args...)> message_type;
+    op->handle_op(message_type(0, static_cast<Args2&&>(args)...));
+  }
+};
+
+template <typename Op>
+class timed_cancel_timer_handler
+{
+public:
+  using cancellation_slot_type = cancellation_slot;
+
+  explicit timed_cancel_timer_handler(Op* op)
+    : op_(op)
+  {
+  }
+
+  timed_cancel_timer_handler(timed_cancel_timer_handler&& other) noexcept
+    : op_(other.op_)
+  {
+    other.op_ = nullptr;
+  }
+
+  ~timed_cancel_timer_handler()
+  {
+    if (op_)
+      op_->release();
+  }
+
+  cancellation_slot_type get_cancellation_slot() const noexcept
+  {
+    return cancellation_slot_type();
+  }
+
+  void operator()(const boost::system::error_code&)
+  {
+    Op* op = op_;
+    op_ = nullptr;
+    op->handle_timer();
+  }
+
+//private:
+  Op* op_;
+};
+
+} // namespace detail
+
+template <template <typename, typename> class Associator,
+    typename Op, typename... Signatures, typename DefaultCandidate>
+struct associator<Associator,
+    detail::timed_cancel_op_handler<Op, Signatures...>, DefaultCandidate>
+  : Associator<typename Op::handler_type, DefaultCandidate>
+{
+  static typename Associator<typename Op::handler_type, DefaultCandidate>::type
+  get(const detail::timed_cancel_op_handler<Op, Signatures...>& h) noexcept
+  {
+    return Associator<typename Op::handler_type, DefaultCandidate>::get(
+        h.op_->handler_);
+  }
+
+  static auto get(const detail::timed_cancel_op_handler<Op, Signatures...>& h,
+      const DefaultCandidate& c) noexcept
+    -> decltype(Associator<typename Op::handler_type, DefaultCandidate>::get(
+        h.op_->handler_, c))
+  {
+    return Associator<typename Op::handler_type, DefaultCandidate>::get(
+        h.op_->handler_, c);
+  }
+};
+
+template <template <typename, typename> class Associator,
+    typename Op, typename DefaultCandidate>
+struct associator<Associator,
+    detail::timed_cancel_timer_handler<Op>, DefaultCandidate>
+  : Associator<typename Op::handler_type, DefaultCandidate>
+{
+  static typename Associator<typename Op::handler_type, DefaultCandidate>::type
+  get(const detail::timed_cancel_timer_handler<Op>& h) noexcept
+  {
+    return Associator<typename Op::handler_type, DefaultCandidate>::get(
+        h.op_->handler_);
+  }
+
+  static auto get(const detail::timed_cancel_timer_handler<Op>& h,
+      const DefaultCandidate& c) noexcept
+    -> decltype(Associator<typename Op::handler_type, DefaultCandidate>::get(
+        h.op_->handler_, c))
+  {
+    return Associator<typename Op::handler_type, DefaultCandidate>::get(
+        h.op_->handler_, c);
+  }
+};
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_DETAIL_TIMED_CANCEL_OP_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/detail/wrapped_handler.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/detail/wrapped_handler.hpp
index 02691c0ec3..4643b71e2d 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/detail/wrapped_handler.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/detail/wrapped_handler.hpp
@@ -42,12 +42,36 @@ struct is_continuation_if_running
   }
 };
 
+template <typename Dispatcher, typename = void>
+struct wrapped_executor
+{
+  typedef Dispatcher executor_type;
+
+  static const Dispatcher& get(const Dispatcher& dispatcher) noexcept
+  {
+    return dispatcher;
+  }
+};
+
+template <typename Dispatcher>
+struct wrapped_executor<Dispatcher,
+    void_type<typename Dispatcher::executor_type>>
+{
+  typedef typename Dispatcher::executor_type executor_type;
+
+  static executor_type get(const Dispatcher& dispatcher) noexcept
+  {
+    return dispatcher.get_executor();
+  }
+};
+
 template <typename Dispatcher, typename Handler,
     typename IsContinuation = is_continuation_delegated>
 class wrapped_handler
 {
 public:
   typedef void result_type;
+  typedef typename wrapped_executor<Dispatcher>::executor_type executor_type;
 
   wrapped_handler(Dispatcher dispatcher, Handler& handler)
     : dispatcher_(dispatcher),
@@ -67,6 +91,11 @@ class wrapped_handler
   {
   }
 
+  executor_type get_executor() const noexcept
+  {
+    return wrapped_executor<Dispatcher>::get(dispatcher_);
+  }
+
   void operator()()
   {
     dispatcher_.dispatch(static_cast<Handler&&>(handler_));
@@ -152,49 +181,6 @@ class wrapped_handler
   Handler handler_;
 };
 
-template <typename Handler, typename Context>
-class rewrapped_handler
-{
-public:
-  explicit rewrapped_handler(Handler& handler, const Context& context)
-    : context_(context),
-      handler_(static_cast<Handler&&>(handler))
-  {
-  }
-
-  explicit rewrapped_handler(const Handler& handler, const Context& context)
-    : context_(context),
-      handler_(handler)
-  {
-  }
-
-  rewrapped_handler(const rewrapped_handler& other)
-    : context_(other.context_),
-      handler_(other.handler_)
-  {
-  }
-
-  rewrapped_handler(rewrapped_handler&& other)
-    : context_(static_cast<Context&&>(other.context_)),
-      handler_(static_cast<Handler&&>(other.handler_))
-  {
-  }
-
-  void operator()()
-  {
-    handler_();
-  }
-
-  void operator()() const
-  {
-    handler_();
-  }
-
-//private:
-  Context context_;
-  Handler handler_;
-};
-
 template <typename Dispatcher, typename Handler, typename IsContinuation>
 inline bool asio_handler_is_continuation(
     wrapped_handler<Dispatcher, Handler, IsContinuation>* this_handler)
@@ -202,14 +188,6 @@ inline bool asio_handler_is_continuation(
   return IsContinuation()(this_handler->dispatcher_, this_handler->handler_);
 }
 
-template <typename Dispatcher, typename Context>
-inline bool asio_handler_is_continuation(
-    rewrapped_handler<Dispatcher, Context>* this_handler)
-{
-  return boost_asio_handler_cont_helpers::is_continuation(
-      this_handler->context_);
-}
-
 } // namespace detail
 } // namespace asio
 } // namespace boost
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/execution/allocator.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/execution/allocator.hpp
index d48f055b87..9fc9c35bb1 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/execution/allocator.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/execution/allocator.hpp
@@ -226,7 +226,7 @@ const T allocator_t<void>::static_query_v;
 #endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
        //   && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
 
-constexpr allocator_t<void> allocator;
+BOOST_ASIO_INLINE_VARIABLE constexpr allocator_t<void> allocator;
 
 } // namespace execution
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/execution/blocking.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/execution/blocking.hpp
index 44d32b24a0..7501aecbc3 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/execution/blocking.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/execution/blocking.hpp
@@ -893,7 +893,7 @@ const T never_t<I>::static_query_v;
 
 typedef detail::blocking_t<> blocking_t;
 
-constexpr blocking_t blocking;
+BOOST_ASIO_INLINE_VARIABLE constexpr blocking_t blocking;
 
 } // namespace execution
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/execution/blocking_adaptation.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/execution/blocking_adaptation.hpp
index 8973a2eb5d..3c641219f4 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/execution/blocking_adaptation.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/execution/blocking_adaptation.hpp
@@ -719,7 +719,7 @@ void blocking_execute(
 
 typedef detail::blocking_adaptation_t<> blocking_adaptation_t;
 
-constexpr blocking_adaptation_t blocking_adaptation;
+BOOST_ASIO_INLINE_VARIABLE constexpr blocking_adaptation_t blocking_adaptation;
 
 } // namespace execution
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/execution/context.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/execution/context.hpp
index 5d8a81b70b..6c9fd9a13d 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/execution/context.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/execution/context.hpp
@@ -139,7 +139,7 @@ const T context_t<I>::static_query_v;
 
 typedef detail::context_t<> context_t;
 
-constexpr context_t context;
+BOOST_ASIO_INLINE_VARIABLE constexpr context_t context;
 
 } // namespace execution
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/execution/mapping.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/execution/mapping.hpp
index 5c668dbb97..769ad8c283 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/execution/mapping.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/execution/mapping.hpp
@@ -734,7 +734,7 @@ const T other_t<I>::static_query_v;
 
 typedef detail::mapping_t<> mapping_t;
 
-constexpr mapping_t mapping;
+BOOST_ASIO_INLINE_VARIABLE constexpr mapping_t mapping;
 
 } // namespace execution
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/execution/occupancy.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/execution/occupancy.hpp
index dddcd84939..20bc40a395 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/execution/occupancy.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/execution/occupancy.hpp
@@ -132,7 +132,7 @@ const T occupancy_t<I>::static_query_v;
 
 typedef detail::occupancy_t<> occupancy_t;
 
-constexpr occupancy_t occupancy;
+BOOST_ASIO_INLINE_VARIABLE constexpr occupancy_t occupancy;
 
 } // namespace execution
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/execution/outstanding_work.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/execution/outstanding_work.hpp
index b8d9677776..f5ea64cebf 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/execution/outstanding_work.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/execution/outstanding_work.hpp
@@ -545,7 +545,7 @@ const T tracked_t<I>::static_query_v;
 
 typedef detail::outstanding_work_t<> outstanding_work_t;
 
-constexpr outstanding_work_t outstanding_work;
+BOOST_ASIO_INLINE_VARIABLE constexpr outstanding_work_t outstanding_work;
 
 } // namespace execution
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/execution/relationship.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/execution/relationship.hpp
index 4ccda00bc2..9cc0fe4f1d 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/execution/relationship.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/execution/relationship.hpp
@@ -543,7 +543,7 @@ const T continuation_t<I>::static_query_v;
 
 typedef detail::relationship_t<> relationship_t;
 
-constexpr relationship_t relationship;
+BOOST_ASIO_INLINE_VARIABLE constexpr relationship_t relationship;
 
 } // namespace execution
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/basic_channel.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/basic_channel.hpp
index c1fc5e0ad2..682884023f 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/basic_channel.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/basic_channel.hpp
@@ -111,7 +111,8 @@ class basic_channel
 
   template <typename... PayloadSignatures,
       BOOST_ASIO_COMPLETION_TOKEN_FOR(PayloadSignatures...) CompletionToken>
-  auto do_async_receive(detail::channel_payload<PayloadSignatures...>*,
+  auto do_async_receive(
+      boost::asio::detail::completion_payload<PayloadSignatures...>*,
       CompletionToken&& token)
     -> decltype(
         async_initiate<CompletionToken, PayloadSignatures...>(
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/basic_concurrent_channel.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/basic_concurrent_channel.hpp
index 33ccef1357..dabab3ecc9 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/basic_concurrent_channel.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/basic_concurrent_channel.hpp
@@ -111,7 +111,8 @@ class basic_concurrent_channel
 
   template <typename... PayloadSignatures,
       BOOST_ASIO_COMPLETION_TOKEN_FOR(PayloadSignatures...) CompletionToken>
-  auto do_async_receive(detail::channel_payload<PayloadSignatures...>*,
+  auto do_async_receive(
+      boost::asio::detail::completion_payload<PayloadSignatures...>*,
       CompletionToken&& token)
     -> decltype(
         async_initiate<CompletionToken, PayloadSignatures...>(
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/co_composed.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/co_composed.hpp
index faa0221ee0..f227631ee6 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/co_composed.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/co_composed.hpp
@@ -16,7 +16,7 @@
 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
 
 #include <boost/asio/detail/config.hpp>
-#include <boost/asio/async_result.hpp>
+#include <boost/asio/co_composed.hpp>
 
 #include <boost/asio/detail/push_options.hpp>
 
@@ -24,117 +24,7 @@ namespace boost {
 namespace asio {
 namespace experimental {
 
-/// Creates an initiation function object that may be used to launch a
-/// coroutine-based composed asynchronous operation.
-/**
- * The experimental::co_composed utility simplifies the implementation of
- * composed asynchronous operations by automatically adapting a coroutine to be
- * an initiation function object for use with @c async_initiate. When awaiting
- * asynchronous operations, the coroutine automatically uses a conforming
- * intermediate completion handler.
- *
- * @param implementation A function object that contains the coroutine-based
- * implementation of the composed asynchronous operation. The first argument to
- * the function object represents the state of the operation, and may be used
- * to test for cancellation. The remaining arguments are those passed to @c
- * async_initiate after the completion token.
- *
- * @param io_objects_or_executors Zero or more I/O objects or I/O executors for
- * which outstanding work must be maintained while the operation is incomplete.
- *
- * @par Per-Operation Cancellation
- * By default, terminal per-operation cancellation is enabled for composed
- * operations that use experimental::co_composed. To disable cancellation for
- * the composed operation, or to alter its supported cancellation types, call
- * the state's @c reset_cancellation_state function.
- *
- * @par Examples
- * The following example illustrates manual error handling and explicit checks
- * for cancellation. The completion handler is invoked via a @c co_yield to the
- * state's @c complete function, which never returns.
- *
- * @code template <typename CompletionToken>
- * auto async_echo(tcp::socket& socket,
- *     CompletionToken&& token)
- * {
- *   return boost::asio::async_initiate<
- *     CompletionToken, void(boost::system::error_code)>(
- *       boost::asio::experimental::co_composed(
- *         [](auto state, tcp::socket& socket) -> void
- *         {
- *           state.reset_cancellation_state(
- *             boost::asio::enable_terminal_cancellation());
- *
- *           while (!state.cancelled())
- *           {
- *             char data[1024];
- *             auto [e1, n1] =
- *               co_await socket.async_read_some(
- *                 boost::asio::buffer(data),
- *                 boost::asio::as_tuple(boost::asio::deferred));
- *
- *             if (e1)
- *               co_yield state.complete(e1);
- *
- *             if (!!state.cancelled())
- *               co_yield state.complete(
- *                 make_error_code(boost::asio::error::operation_aborted));
- *
- *             auto [e2, n2] =
- *               co_await boost::asio::async_write(socket,
- *                 boost::asio::buffer(data, n1),
- *                 boost::asio::as_tuple(boost::asio::deferred));
- *
- *             if (e2)
- *               co_yield state.complete(e2);
- *           }
- *         }, socket),
- *       token, std::ref(socket));
- * } @endcode
- *
- * This next example shows exception-based error handling and implicit checks
- * for cancellation. The completion handler is invoked after returning from the
- * coroutine via @c co_return. Valid @c co_return values are specified using
- * completion signatures passed to the @c co_composed function.
- *
- * @code template <typename CompletionToken>
- * auto async_echo(tcp::socket& socket,
- *     CompletionToken&& token)
- * {
- *   return boost::asio::async_initiate<
- *     CompletionToken, void(boost::system::error_code)>(
- *       boost::asio::experimental::co_composed<
- *         void(boost::system::error_code)>(
- *           [](auto state, tcp::socket& socket) -> void
- *           {
- *             try
- *             {
- *               state.throw_if_cancelled(true);
- *               state.reset_cancellation_state(
- *                 boost::asio::enable_terminal_cancellation());
- *
- *               for (;;)
- *               {
- *                 char data[1024];
- *                 std::size_t n = co_await socket.async_read_some(
- *                     boost::asio::buffer(data), boost::asio::deferred);
- *
- *                 co_await boost::asio::async_write(socket,
- *                     boost::asio::buffer(data, n), boost::asio::deferred);
- *               }
- *             }
- *             catch (const boost::system::system_error& e)
- *             {
- *               co_return {e.code()};
- *             }
- *           }, socket),
- *       token, std::ref(socket));
- * } @endcode
- */
-template <completion_signature... Signatures,
-    typename Implementation, typename... IoObjectsOrExecutors>
-auto co_composed(Implementation&& implementation,
-    IoObjectsOrExecutors&&... io_objects_or_executors);
+using boost::asio::co_composed;
 
 } // namespace experimental
 } // namespace asio
@@ -142,6 +32,4 @@ auto co_composed(Implementation&& implementation,
 
 #include <boost/asio/detail/pop_options.hpp>
 
-#include <boost/asio/experimental/impl/co_composed.hpp>
-
 #endif // BOOST_ASIO_EXPERIMENTAL_CO_COMPOSED_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_receive_op.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_receive_op.hpp
index 76a09a4d36..5ed64e445b 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_receive_op.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_receive_op.hpp
@@ -17,11 +17,10 @@
 
 #include <boost/asio/detail/config.hpp>
 #include <boost/asio/detail/bind_handler.hpp>
+#include <boost/asio/detail/completion_handler.hpp>
 #include <boost/asio/detail/handler_alloc_helpers.hpp>
 #include <boost/asio/error.hpp>
-#include <boost/asio/experimental/detail/channel_handler.hpp>
 #include <boost/asio/experimental/detail/channel_operation.hpp>
-#include <boost/asio/experimental/detail/channel_payload.hpp>
 
 #include <boost/asio/detail/push_options.hpp>
 
@@ -93,7 +92,7 @@ class channel_receive_op : public channel_receive<Payload>
     if (a != channel_operation::destroy_op)
     {
       Payload* payload = static_cast<Payload*>(v);
-      channel_handler<Payload, Handler> handler(
+      boost::asio::detail::completion_payload_handler<Payload, Handler> handler(
           static_cast<Payload&&>(*payload), o->handler_);
       p.h = boost::asio::detail::addressof(handler.handler_);
       p.reset();
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_send_functions.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_send_functions.hpp
index 4587ae3f6e..b748f8ba5a 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_send_functions.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_send_functions.hpp
@@ -17,9 +17,9 @@
 
 #include <boost/asio/detail/config.hpp>
 #include <boost/asio/async_result.hpp>
+#include <boost/asio/detail/completion_message.hpp>
 #include <boost/asio/detail/type_traits.hpp>
 #include <boost/system/error_code.hpp>
-#include <boost/asio/experimental/detail/channel_message.hpp>
 
 #include <boost/asio/detail/push_options.hpp>
 
@@ -37,11 +37,12 @@ class channel_send_functions<Derived, Executor, R(Args...)>
 public:
   template <typename... Args2>
   enable_if_t<
-    is_constructible<detail::channel_message<R(Args...)>, int, Args2...>::value,
+    is_constructible<boost::asio::detail::completion_message<R(Args...)>,
+      int, Args2...>::value,
     bool
   > try_send(Args2&&... args)
   {
-    typedef typename detail::channel_message<R(Args...)> message_type;
+    typedef boost::asio::detail::completion_message<R(Args...)> message_type;
     Derived* self = static_cast<Derived*>(this);
     return self->service_->template try_send<message_type>(
         self->impl_, false, static_cast<Args2&&>(args)...);
@@ -49,11 +50,12 @@ class channel_send_functions<Derived, Executor, R(Args...)>
 
   template <typename... Args2>
   enable_if_t<
-    is_constructible<detail::channel_message<R(Args...)>, int, Args2...>::value,
+    is_constructible<boost::asio::detail::completion_message<R(Args...)>,
+      int, Args2...>::value,
     bool
   > try_send_via_dispatch(Args2&&... args)
   {
-    typedef typename detail::channel_message<R(Args...)> message_type;
+    typedef boost::asio::detail::completion_message<R(Args...)> message_type;
     Derived* self = static_cast<Derived*>(this);
     return self->service_->template try_send<message_type>(
         self->impl_, true, static_cast<Args2&&>(args)...);
@@ -61,11 +63,12 @@ class channel_send_functions<Derived, Executor, R(Args...)>
 
   template <typename... Args2>
   enable_if_t<
-    is_constructible<detail::channel_message<R(Args...)>, int, Args2...>::value,
+    is_constructible<boost::asio::detail::completion_message<R(Args...)>,
+      int, Args2...>::value,
     std::size_t
   > try_send_n(std::size_t count, Args2&&... args)
   {
-    typedef typename detail::channel_message<R(Args...)> message_type;
+    typedef boost::asio::detail::completion_message<R(Args...)> message_type;
     Derived* self = static_cast<Derived*>(this);
     return self->service_->template try_send_n<message_type>(
         self->impl_, count, false, static_cast<Args2&&>(args)...);
@@ -73,11 +76,12 @@ class channel_send_functions<Derived, Executor, R(Args...)>
 
   template <typename... Args2>
   enable_if_t<
-    is_constructible<detail::channel_message<R(Args...)>, int, Args2...>::value,
+    is_constructible<boost::asio::detail::completion_message<R(Args...)>,
+      int, Args2...>::value,
     std::size_t
   > try_send_n_via_dispatch(std::size_t count, Args2&&... args)
   {
-    typedef typename detail::channel_message<R(Args...)> message_type;
+    typedef boost::asio::detail::completion_message<R(Args...)> message_type;
     Derived* self = static_cast<Derived*>(this);
     return self->service_->template try_send_n<message_type>(
         self->impl_, count, true, static_cast<Args2&&>(args)...);
@@ -97,7 +101,7 @@ class channel_send_functions<Derived, Executor, R(Args...)>
             Derived>::payload_type>()))
   {
     typedef typename Derived::payload_type payload_type;
-    typedef typename detail::channel_message<R(Args...)> message_type;
+    typedef boost::asio::detail::completion_message<R(Args...)> message_type;
     Derived* self = static_cast<Derived*>(this);
     return async_initiate<CompletionToken, void (boost::system::error_code)>(
         typename Derived::initiate_async_send(self), token,
@@ -116,11 +120,12 @@ class channel_send_functions<Derived, Executor, R(Args...), Signatures...> :
 
   template <typename... Args2>
   enable_if_t<
-    is_constructible<detail::channel_message<R(Args...)>, int, Args2...>::value,
+    is_constructible<boost::asio::detail::completion_message<R(Args...)>,
+      int, Args2...>::value,
     bool
   > try_send(Args2&&... args)
   {
-    typedef typename detail::channel_message<R(Args...)> message_type;
+    typedef boost::asio::detail::completion_message<R(Args...)> message_type;
     Derived* self = static_cast<Derived*>(this);
     return self->service_->template try_send<message_type>(
         self->impl_, false, static_cast<Args2&&>(args)...);
@@ -128,11 +133,12 @@ class channel_send_functions<Derived, Executor, R(Args...), Signatures...> :
 
   template <typename... Args2>
   enable_if_t<
-    is_constructible<detail::channel_message<R(Args...)>, int, Args2...>::value,
+    is_constructible<boost::asio::detail::completion_message<R(Args...)>,
+      int, Args2...>::value,
     bool
   > try_send_via_dispatch(Args2&&... args)
   {
-    typedef typename detail::channel_message<R(Args...)> message_type;
+    typedef boost::asio::detail::completion_message<R(Args...)> message_type;
     Derived* self = static_cast<Derived*>(this);
     return self->service_->template try_send<message_type>(
         self->impl_, true, static_cast<Args2&&>(args)...);
@@ -140,11 +146,12 @@ class channel_send_functions<Derived, Executor, R(Args...), Signatures...> :
 
   template <typename... Args2>
   enable_if_t<
-    is_constructible<detail::channel_message<R(Args...)>, int, Args2...>::value,
+    is_constructible<boost::asio::detail::completion_message<R(Args...)>,
+      int, Args2...>::value,
     std::size_t
   > try_send_n(std::size_t count, Args2&&... args)
   {
-    typedef typename detail::channel_message<R(Args...)> message_type;
+    typedef boost::asio::detail::completion_message<R(Args...)> message_type;
     Derived* self = static_cast<Derived*>(this);
     return self->service_->template try_send_n<message_type>(
         self->impl_, count, false, static_cast<Args2&&>(args)...);
@@ -152,11 +159,12 @@ class channel_send_functions<Derived, Executor, R(Args...), Signatures...> :
 
   template <typename... Args2>
   enable_if_t<
-    is_constructible<detail::channel_message<R(Args...)>, int, Args2...>::value,
+    is_constructible<boost::asio::detail::completion_message<R(Args...)>,
+      int, Args2...>::value,
     std::size_t
   > try_send_n_via_dispatch(std::size_t count, Args2&&... args)
   {
-    typedef typename detail::channel_message<R(Args...)> message_type;
+    typedef boost::asio::detail::completion_message<R(Args...)> message_type;
     Derived* self = static_cast<Derived*>(this);
     return self->service_->template try_send_n<message_type>(
         self->impl_, count, true, static_cast<Args2&&>(args)...);
@@ -176,7 +184,7 @@ class channel_send_functions<Derived, Executor, R(Args...), Signatures...> :
             Derived>::payload_type>()))
   {
     typedef typename Derived::payload_type payload_type;
-    typedef typename detail::channel_message<R(Args...)> message_type;
+    typedef boost::asio::detail::completion_message<R(Args...)> message_type;
     Derived* self = static_cast<Derived*>(this);
     return async_initiate<CompletionToken, void (boost::system::error_code)>(
         typename Derived::initiate_async_send(self), token,
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_send_op.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_send_op.hpp
index aca8de826d..49b444c19b 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_send_op.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_send_op.hpp
@@ -21,7 +21,6 @@
 #include <boost/asio/error.hpp>
 #include <boost/asio/experimental/channel_error.hpp>
 #include <boost/asio/experimental/detail/channel_operation.hpp>
-#include <boost/asio/experimental/detail/channel_payload.hpp>
 
 #include <boost/asio/detail/push_options.hpp>
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_service.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_service.hpp
index 819aad114b..341797f1b6 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_service.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/channel_service.hpp
@@ -18,10 +18,12 @@
 #include <boost/asio/detail/config.hpp>
 #include <boost/asio/associated_cancellation_slot.hpp>
 #include <boost/asio/cancellation_type.hpp>
+#include <boost/asio/detail/completion_message.hpp>
+#include <boost/asio/detail/completion_payload.hpp>
+#include <boost/asio/detail/completion_payload_handler.hpp>
 #include <boost/asio/detail/mutex.hpp>
 #include <boost/asio/detail/op_queue.hpp>
 #include <boost/asio/execution_context.hpp>
-#include <boost/asio/experimental/detail/channel_message.hpp>
 #include <boost/asio/experimental/detail/channel_receive_op.hpp>
 #include <boost/asio/experimental/detail/channel_send_op.hpp>
 #include <boost/asio/experimental/detail/has_signature.hpp>
@@ -232,7 +234,7 @@ class channel_service
     void operator()(Args&&... args)
     {
       op_->post(
-          channel_message<Signature>(0,
+          boost::asio::detail::completion_message<Signature>(0,
             static_cast<Args&&>(args)...));
     }
 
@@ -308,8 +310,8 @@ struct channel_service<Mutex>::implementation_type : base_implementation_type
           typename traits_type::receive_closed_signature,
           Signatures...
         >::value,
-        channel_payload<Signatures...>,
-        channel_payload<
+        boost::asio::detail::completion_payload<Signatures...>,
+        boost::asio::detail::completion_payload<
           Signatures...,
           typename traits_type::receive_closed_signature
         >
@@ -320,11 +322,11 @@ struct channel_service<Mutex>::implementation_type : base_implementation_type
           Signatures...,
           typename traits_type::receive_cancelled_signature
         >::value,
-        channel_payload<
+        boost::asio::detail::completion_payload<
           Signatures...,
           typename traits_type::receive_cancelled_signature
         >,
-        channel_payload<
+        boost::asio::detail::completion_payload<
           Signatures...,
           typename traits_type::receive_cancelled_signature,
           typename traits_type::receive_closed_signature
@@ -405,8 +407,8 @@ struct channel_service<Mutex>::implementation_type<Traits, R()>
           typename traits_type::receive_closed_signature,
           R()
         >::value,
-        channel_payload<R()>,
-        channel_payload<
+        boost::asio::detail::completion_payload<R()>,
+        boost::asio::detail::completion_payload<
           R(),
           typename traits_type::receive_closed_signature
         >
@@ -417,11 +419,11 @@ struct channel_service<Mutex>::implementation_type<Traits, R()>
           R(),
           typename traits_type::receive_cancelled_signature
         >::value,
-        channel_payload<
+        boost::asio::detail::completion_payload<
           R(),
           typename traits_type::receive_cancelled_signature
         >,
-        channel_payload<
+        boost::asio::detail::completion_payload<
           R(),
           typename traits_type::receive_cancelled_signature,
           typename traits_type::receive_closed_signature
@@ -466,7 +468,7 @@ struct channel_service<Mutex>::implementation_type<Traits, R()>
   // Get the element at the front of the buffer.
   payload_type buffer_front()
   {
-    return payload_type(channel_message<R()>(0));
+    return payload_type(boost::asio::detail::completion_message<R()>(0));
   }
 
   // Pop a value from the front of the buffer.
@@ -508,8 +510,8 @@ struct channel_service<Mutex>::implementation_type<
           typename traits_type::receive_closed_signature,
           R(boost::system::error_code)
         >::value,
-        channel_payload<R(boost::system::error_code)>,
-        channel_payload<
+        boost::asio::detail::completion_payload<R(boost::system::error_code)>,
+        boost::asio::detail::completion_payload<
           R(boost::system::error_code),
           typename traits_type::receive_closed_signature
         >
@@ -520,11 +522,11 @@ struct channel_service<Mutex>::implementation_type<
           R(boost::system::error_code),
           typename traits_type::receive_cancelled_signature
         >::value,
-        channel_payload<
+        boost::asio::detail::completion_payload<
           R(boost::system::error_code),
           typename traits_type::receive_cancelled_signature
         >,
-        channel_payload<
+        boost::asio::detail::completion_payload<
           R(boost::system::error_code),
           typename traits_type::receive_cancelled_signature,
           typename traits_type::receive_closed_signature
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/coro_promise_allocator.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/coro_promise_allocator.hpp
index 322ecbbef2..c4e534fda1 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/coro_promise_allocator.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/coro_promise_allocator.hpp
@@ -65,7 +65,6 @@ constexpr std::size_t variadic_first(std::size_t = 0u)
   return std::numeric_limits<std::size_t>::max();
 }
 
-
 template <typename T, typename First, typename... Args>
 constexpr std::size_t variadic_first(std::size_t pos = 0u)
 {
@@ -95,14 +94,14 @@ struct coro_promise_allocator
   allocator_type get_allocator() const {return alloc_;}
 
   template <typename... Args>
-  void* operator new(const std::size_t size, Args & ... args)
+  void* operator new(std::size_t size, Args & ... args)
   {
     return allocate_coroutine(size,
         get_variadic<variadic_first<std::allocator_arg_t,
           std::decay_t<Args>...>() + 1u>(args...));
   }
 
-  void operator delete(void* raw, const std::size_t size)
+  void operator delete(void* raw, std::size_t size)
   {
     deallocate_coroutine<allocator_type>(raw, size);
   }
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/impl/channel_service.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/impl/channel_service.hpp
index 8b7b2e2273..eb672be511 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/impl/channel_service.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/impl/channel_service.hpp
@@ -518,7 +518,8 @@ bool channel_service<Mutex>::try_receive(
       }
       lock.unlock();
       boost::asio::detail::non_const_lvalue<Handler> handler2(handler);
-      channel_handler<payload_type, decay_t<Handler>>(
+      boost::asio::detail::completion_payload_handler<
+        payload_type, decay_t<Handler>>(
           static_cast<payload_type&&>(payload), handler2.value)();
       return true;
     }
@@ -533,7 +534,8 @@ bool channel_service<Mutex>::try_receive(
       send_op->post();
       lock.unlock();
       boost::asio::detail::non_const_lvalue<Handler> handler2(handler);
-      channel_handler<payload_type, decay_t<Handler>>(
+      boost::asio::detail::completion_payload_handler<
+        payload_type, decay_t<Handler>>(
           static_cast<payload_type&&>(payload), handler2.value)();
       return true;
     }
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/partial_promise.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/partial_promise.hpp
index 24a6676ff6..2dde763876 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/partial_promise.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/detail/partial_promise.hpp
@@ -55,12 +55,12 @@ template <typename Allocator>
 struct partial_promise_base
 {
   template <typename Executor, typename Token, typename... Args>
-  void* operator new(const std::size_t size, Executor&, Token& tk, Args&...)
+  void* operator new(std::size_t size, Executor&, Token& tk, Args&...)
   {
     return allocate_coroutine<Allocator>(size, get_associated_allocator(tk));
   }
 
-  void operator delete(void* raw, const std::size_t size)
+  void operator delete(void* raw, std::size_t size)
   {
     deallocate_coroutine<Allocator>(raw, size);
   }
@@ -111,9 +111,7 @@ struct partial_promise : partial_promise_base<Allocator>
   }
 };
 
-
-
-}; // namespace detail
+} // namespace detail
 } // namespace experimental
 } // namespace asio
 } // namespace boost
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/impl/as_single.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/impl/as_single.hpp
index 81841fb3be..14a822ae66 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/impl/as_single.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/impl/as_single.hpp
@@ -20,6 +20,7 @@
 #include <boost/asio/associator.hpp>
 #include <boost/asio/async_result.hpp>
 #include <boost/asio/detail/handler_cont_helpers.hpp>
+#include <boost/asio/detail/initiation_base.hpp>
 #include <boost/asio/detail/type_traits.hpp>
 
 #include <boost/asio/detail/push_options.hpp>
@@ -111,23 +112,27 @@ template <typename CompletionToken, typename Signature>
 struct async_result<experimental::as_single_t<CompletionToken>, Signature>
 {
   template <typename Initiation>
-  struct init_wrapper
+  struct init_wrapper : detail::initiation_base<Initiation>
   {
-    init_wrapper(Initiation init)
-      : initiation_(static_cast<Initiation&&>(init))
+    using detail::initiation_base<Initiation>::initiation_base;
+
+    template <typename Handler, typename... Args>
+    void operator()(Handler&& handler, Args&&... args) &&
     {
+      static_cast<Initiation&&>(*this)(
+          experimental::detail::as_single_handler<decay_t<Handler>>(
+            static_cast<Handler&&>(handler)),
+          static_cast<Args&&>(args)...);
     }
 
     template <typename Handler, typename... Args>
-    void operator()(Handler&& handler, Args&&... args)
+    void operator()(Handler&& handler, Args&&... args) const &
     {
-      static_cast<Initiation&&>(initiation_)(
+      static_cast<const Initiation&>(*this)(
           experimental::detail::as_single_handler<decay_t<Handler>>(
             static_cast<Handler&&>(handler)),
           static_cast<Args&&>(args)...);
     }
-
-    Initiation initiation_;
   };
 
   template <typename Initiation, typename RawCompletionToken, typename... Args>
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/impl/coro.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/impl/coro.hpp
index 6e0bf0cc77..80f2b4e3fb 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/impl/coro.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/impl/coro.hpp
@@ -601,7 +601,7 @@ struct coro_promise final :
 
   cancellation_slot_type get_cancellation_slot() const noexcept
   {
-    return cancel ? cancel->slot : cancellation_slot_type{};
+    return cancel ? cancel->state.slot() : cancellation_slot_type{};
   }
 
   using allocator_type =
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/parallel_group.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/parallel_group.hpp
index cdaa753377..e283e3fb1e 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/parallel_group.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/parallel_group.hpp
@@ -208,6 +208,36 @@ class parallel_group
 /**
  * For example:
  * @code boost::asio::experimental::make_parallel_group(
+ *    in.async_read_some(boost::asio::buffer(data)),
+ *    timer.async_wait()
+ *  ).async_wait(
+ *    boost::asio::experimental::wait_for_all(),
+ *    [](
+ *        std::array<std::size_t, 2> completion_order,
+ *        boost::system::error_code ec1, std::size_t n1,
+ *        boost::system::error_code ec2
+ *    )
+ *    {
+ *      switch (completion_order[0])
+ *      {
+ *      case 0:
+ *        {
+ *          std::cout << "descriptor finished: " << ec1 << ", " << n1 << "\n";
+ *        }
+ *        break;
+ *      case 1:
+ *        {
+ *          std::cout << "timer finished: " << ec2 << "\n";
+ *        }
+ *        break;
+ *      }
+ *    }
+ *  );
+ * @endcode
+ *
+ * If preferred, the asynchronous operations may be explicitly packaged as
+ * function objects:
+ * @code boost::asio::experimental::make_parallel_group(
  *    [&](auto token)
  *    {
  *      return in.async_read_some(boost::asio::buffer(data), token);
@@ -333,28 +363,12 @@ class ranged_parallel_group
  *
  * For example:
  * @code
- * using op_type = decltype(
- *     socket1.async_read_some(
- *       boost::asio::buffer(data1),
- *       boost::asio::deferred
- *     )
- *   );
+ * using op_type =
+ *   decltype(socket1.async_read_some(boost::asio::buffer(data1)));
  *
  * std::vector<op_type> ops;
- *
- * ops.push_back(
- *     socket1.async_read_some(
- *       boost::asio::buffer(data1),
- *       boost::asio::deferred
- *     )
- *   );
- *
- * ops.push_back(
- *     socket2.async_read_some(
- *       boost::asio::buffer(data2),
- *       boost::asio::deferred
- *     )
- *   );
+ * ops.push_back(socket1.async_read_some(boost::asio::buffer(data1)));
+ * ops.push_back(socket2.async_read_some(boost::asio::buffer(data2)));
  *
  * boost::asio::experimental::make_parallel_group(ops).async_wait(
  *     boost::asio::experimental::wait_for_all(),
@@ -392,28 +406,12 @@ make_parallel_group(Range&& range,
  *
  * For example:
  * @code
- * using op_type = decltype(
- *     socket1.async_read_some(
- *       boost::asio::buffer(data1),
- *       boost::asio::deferred
- *     )
- *   );
+ * using op_type =
+ *   decltype(socket1.async_read_some(boost::asio::buffer(data1)));
  *
  * std::vector<op_type> ops;
- *
- * ops.push_back(
- *     socket1.async_read_some(
- *       boost::asio::buffer(data1),
- *       boost::asio::deferred
- *     )
- *   );
- *
- * ops.push_back(
- *     socket2.async_read_some(
- *       boost::asio::buffer(data2),
- *       boost::asio::deferred
- *     )
- *   );
+ * ops.push_back(socket1.async_read_some(boost::asio::buffer(data1)));
+ * ops.push_back(socket2.async_read_some(boost::asio::buffer(data2)));
  *
  * boost::asio::experimental::make_parallel_group(
  *     std::allocator_arg_t,
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/promise.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/promise.hpp
index 205d795456..e118007b5e 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/promise.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/promise.hpp
@@ -85,8 +85,9 @@ struct promise_value_type<>
  * awaitable<void> read_write_some(boost::asio::ip::tcp::socket & sock,
  *     boost::asio::mutable_buffer read_buf, boost::asio::const_buffer to_write)
  * {
- *   auto p = boost::asio::async_read(read_buf, boost::asio::use_awaitable);
- *   co_await boost::asio::async_write_some(to_write, boost::asio::deferred);
+ *   auto p = boost::asio::async_read(read_buf,
+ *       boost::asio::experimental::use_promise);
+ *   co_await boost::asio::async_write_some(to_write);
  *   co_await p;
  * }
  * @endcode
@@ -140,7 +141,6 @@ struct promise<void(Ts...), Executor,  Allocator>
    */
   ~promise() { cancel(); }
 
-
 private:
 #if !defined(GENERATING_DOCUMENTATION)
   template <typename, typename, typename> friend struct promise;
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/use_coro.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/use_coro.hpp
index 133a23aa21..d8d0d35585 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/use_coro.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/use_coro.hpp
@@ -48,8 +48,9 @@ namespace experimental {
  * the asynchronous operation completes, and the result of the operation is
  * returned.
  *
- * Note that this token is not the most efficient (use @c boost::asio::deferred
- * for that) but does provide type erasure, as it will always return a @c coro.
+ * Note that this token is not the most efficient (use the default completion
+ * token @c boost::asio::deferred for that) but does provide type erasure, as it
+ * will always return a @c coro.
  */
 template <typename Allocator = std::allocator<void>>
 struct use_coro_t
@@ -84,7 +85,6 @@ struct use_coro_t
   {
   }
 
-
   /// Specify an alternate allocator.
   template <typename OtherAllocator>
   use_coro_t<OtherAllocator> rebind(const OtherAllocator& allocator) const
@@ -174,9 +174,9 @@ struct use_coro_t
  * See the documentation for boost::asio::use_coro_t for a usage example.
  */
 #if defined(GENERATING_DOCUMENTATION)
-constexpr use_coro_t<> use_coro;
+BOOST_ASIO_INLINE_VARIABLE constexpr use_coro_t<> use_coro;
 #else
-constexpr use_coro_t<> use_coro(0, 0, 0);
+BOOST_ASIO_INLINE_VARIABLE constexpr use_coro_t<> use_coro(0, 0, 0);
 #endif
 
 } // namespace experimental
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/use_promise.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/use_promise.hpp
index a2fa9d51bc..e78921a412 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/experimental/use_promise.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/experimental/use_promise.hpp
@@ -100,7 +100,7 @@ struct use_promise_t
   Allocator allocator_;
 };
 
-constexpr use_promise_t<> use_promise;
+BOOST_ASIO_INLINE_VARIABLE constexpr use_promise_t<> use_promise;
 
 } // namespace experimental
 } // namespace asio
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/immediate.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/immediate.hpp
new file mode 100644
index 0000000000..c5ff2f67ad
--- /dev/null
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/immediate.hpp
@@ -0,0 +1,144 @@
+//
+// immediate.hpp
+// ~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_IMMEDIATE_HPP
+#define BOOST_ASIO_IMMEDIATE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/associated_immediate_executor.hpp>
+#include <boost/asio/async_result.hpp>
+#include <boost/asio/dispatch.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename Executor>
+class initiate_immediate
+{
+public:
+  typedef Executor executor_type;
+
+  explicit initiate_immediate(const Executor& ex)
+    : ex_(ex)
+  {
+  }
+
+  executor_type get_executor() const noexcept
+  {
+    return ex_;
+  }
+
+  template <typename CompletionHandler>
+  void operator()(CompletionHandler&& handler) const
+  {
+    typename associated_immediate_executor<
+      CompletionHandler, executor_type>::type ex =
+        (get_associated_immediate_executor)(handler, ex_);
+    (dispatch)(ex, static_cast<CompletionHandler&&>(handler));
+  }
+
+private:
+  Executor ex_;
+};
+
+} // namespace detail
+
+/// Launch a trivial asynchronous operation that completes immediately.
+/**
+ * The async_immediate function is intended for use by composed operations,
+ * which can delegate to this operation in order to implement the correct
+ * semantics for immediate completion.
+ *
+ * @param ex The asynchronous operation's I/O executor.
+ *
+ * @param token The completion token.
+ *
+ * The completion handler is immediately submitted for execution by calling
+ * boost::asio::dispatch() on the handler's associated immediate executor.
+ *
+ * If the completion handler does not have a customised associated immediate
+ * executor, then the handler is submitted as if by calling boost::asio::post()
+ * on the supplied I/O executor.
+ *
+ * @par Completion Signature
+ * @code void() @endcode
+ */
+template <typename Executor,
+    BOOST_ASIO_COMPLETION_TOKEN_FOR(void()) NullaryToken
+      = default_completion_token_t<Executor>>
+inline auto async_immediate(const Executor& ex,
+    NullaryToken&& token = default_completion_token_t<Executor>(),
+    constraint_t<
+      (execution::is_executor<Executor>::value
+          && can_require<Executor, execution::blocking_t::never_t>::value)
+        || is_executor<Executor>::value
+    > = 0)
+  -> decltype(
+    async_initiate<NullaryToken, void()>(
+      declval<detail::initiate_immediate<Executor>>(), token))
+{
+  return async_initiate<NullaryToken, void()>(
+      detail::initiate_immediate<Executor>(ex), token);
+}
+
+/// Launch a trivial asynchronous operation that completes immediately.
+/**
+ * The async_immediate function is intended for use by composed operations,
+ * which can delegate to this operation in order to implement the correct
+ * semantics for immediate completion.
+ *
+ * @param ex The execution context used to obtain the asynchronous operation's
+ * I/O executor.
+ *
+ * @param token The completion token.
+ *
+ * The completion handler is immediately submitted for execution by calling
+ * boost::asio::dispatch() on the handler's associated immediate executor.
+ *
+ * If the completion handler does not have a customised associated immediate
+ * executor, then the handler is submitted as if by calling boost::asio::post()
+ * on the I/O executor obtained from the supplied execution context.
+ *
+ * @par Completion Signature
+ * @code void() @endcode
+ */
+template <typename ExecutionContext,
+    BOOST_ASIO_COMPLETION_TOKEN_FOR(void()) NullaryToken
+      = default_completion_token_t<typename ExecutionContext::executor_type>>
+inline auto async_immediate(ExecutionContext& ctx,
+    NullaryToken&& token = default_completion_token_t<
+      typename ExecutionContext::executor_type>(),
+    constraint_t<
+      is_convertible<ExecutionContext&, execution_context&>::value
+    > = 0)
+  -> decltype(
+    async_initiate<NullaryToken, void()>(
+      declval<detail::initiate_immediate<
+        typename ExecutionContext::executor_type>>(), token))
+{
+  return async_initiate<NullaryToken, void()>(
+      detail::initiate_immediate<
+        typename ExecutionContext::executor_type>(
+          ctx.get_executor()), token);
+}
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_IMMEDIATE_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/append.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/append.hpp
index 2e409e0dfe..e358ea2b07 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/impl/append.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/append.hpp
@@ -19,6 +19,7 @@
 #include <boost/asio/associator.hpp>
 #include <boost/asio/async_result.hpp>
 #include <boost/asio/detail/handler_cont_helpers.hpp>
+#include <boost/asio/detail/initiation_base.hpp>
 #include <boost/asio/detail/type_traits.hpp>
 #include <boost/asio/detail/utility.hpp>
 
@@ -94,25 +95,31 @@ struct async_result<append_t<CompletionToken, Values...>, Signature>
       Signature, Values...>::type signature;
 
   template <typename Initiation>
-  struct init_wrapper
+  struct init_wrapper : detail::initiation_base<Initiation>
   {
-    init_wrapper(Initiation init)
-      : initiation_(static_cast<Initiation&&>(init))
+    using detail::initiation_base<Initiation>::initiation_base;
+
+    template <typename Handler, typename... Args>
+    void operator()(Handler&& handler,
+        std::tuple<Values...> values, Args&&... args) &&
     {
+      static_cast<Initiation&&>(*this)(
+          detail::append_handler<decay_t<Handler>, Values...>(
+            static_cast<Handler&&>(handler),
+            static_cast<std::tuple<Values...>&&>(values)),
+          static_cast<Args&&>(args)...);
     }
 
     template <typename Handler, typename... Args>
     void operator()(Handler&& handler,
-        std::tuple<Values...> values, Args&&... args)
+        std::tuple<Values...> values, Args&&... args) const &
     {
-      static_cast<Initiation&&>(initiation_)(
+      static_cast<const Initiation&>(*this)(
           detail::append_handler<decay_t<Handler>, Values...>(
             static_cast<Handler&&>(handler),
             static_cast<std::tuple<Values...>&&>(values)),
           static_cast<Args&&>(args)...);
     }
-
-    Initiation initiation_;
   };
 
   template <typename Initiation, typename RawCompletionToken, typename... Args>
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/as_tuple.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/as_tuple.hpp
index 780b271d05..912e2666f9 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/impl/as_tuple.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/as_tuple.hpp
@@ -17,9 +17,11 @@
 
 #include <boost/asio/detail/config.hpp>
 #include <tuple>
+#include <boost/asio/associated_executor.hpp>
 #include <boost/asio/associator.hpp>
 #include <boost/asio/async_result.hpp>
 #include <boost/asio/detail/handler_cont_helpers.hpp>
+#include <boost/asio/detail/initiation_base.hpp>
 #include <boost/asio/detail/type_traits.hpp>
 
 #include <boost/asio/detail/push_options.hpp>
@@ -119,23 +121,27 @@ struct async_result<as_tuple_t<CompletionToken>, Signatures...>
       typename detail::as_tuple_signature<Signatures>::type...>
 {
   template <typename Initiation>
-  struct init_wrapper
+  struct init_wrapper : detail::initiation_base<Initiation>
   {
-    init_wrapper(Initiation init)
-      : initiation_(static_cast<Initiation&&>(init))
+    using detail::initiation_base<Initiation>::initiation_base;
+
+    template <typename Handler, typename... Args>
+    void operator()(Handler&& handler, Args&&... args) &&
     {
+      static_cast<Initiation&&>(*this)(
+          detail::as_tuple_handler<decay_t<Handler>>(
+            static_cast<Handler&&>(handler)),
+          static_cast<Args&&>(args)...);
     }
 
     template <typename Handler, typename... Args>
-    void operator()(Handler&& handler, Args&&... args)
+    void operator()(Handler&& handler, Args&&... args) const &
     {
-      static_cast<Initiation&&>(initiation_)(
+      static_cast<const Initiation&>(*this)(
           detail::as_tuple_handler<decay_t<Handler>>(
             static_cast<Handler&&>(handler)),
           static_cast<Args&&>(args)...);
     }
-
-    Initiation initiation_;
   };
 
   template <typename Initiation, typename RawCompletionToken, typename... Args>
@@ -172,23 +178,27 @@ struct async_result<as_tuple_t<CompletionToken>, Signature>
       typename detail::as_tuple_signature<Signature>::type>
 {
   template <typename Initiation>
-  struct init_wrapper
+  struct init_wrapper : detail::initiation_base<Initiation>
   {
-    init_wrapper(Initiation init)
-      : initiation_(static_cast<Initiation&&>(init))
+    using detail::initiation_base<Initiation>::initiation_base;
+
+    template <typename Handler, typename... Args>
+    void operator()(Handler&& handler, Args&&... args) &&
     {
+      static_cast<Initiation&&>(*this)(
+          detail::as_tuple_handler<decay_t<Handler>>(
+            static_cast<Handler&&>(handler)),
+          static_cast<Args&&>(args)...);
     }
 
     template <typename Handler, typename... Args>
-    void operator()(Handler&& handler, Args&&... args)
+    void operator()(Handler&& handler, Args&&... args) const &
     {
-      static_cast<Initiation&&>(initiation_)(
+      static_cast<const Initiation&>(*this)(
           detail::as_tuple_handler<decay_t<Handler>>(
             static_cast<Handler&&>(handler)),
           static_cast<Args&&>(args)...);
     }
-
-    Initiation initiation_;
   };
 
   template <typename Initiation, typename RawCompletionToken, typename... Args>
@@ -237,6 +247,27 @@ struct associator<Associator,
   }
 };
 
+template <typename... Signatures>
+struct async_result<partial_as_tuple, Signatures...>
+{
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static auto initiate(Initiation&& initiation,
+      RawCompletionToken&&, Args&&... args)
+    -> decltype(
+      async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        as_tuple_t<
+          default_completion_token_t<associated_executor_t<Initiation>>>{},
+        static_cast<Args&&>(args)...))
+  {
+    return async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        as_tuple_t<
+          default_completion_token_t<associated_executor_t<Initiation>>>{},
+        static_cast<Args&&>(args)...);
+  }
+};
+
 #endif // !defined(GENERATING_DOCUMENTATION)
 
 } // namespace asio
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/awaitable.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/awaitable.hpp
index 09833ead27..477a45acff 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/impl/awaitable.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/awaitable.hpp
@@ -546,7 +546,7 @@ class awaitable_frame
   {
     this->coro_ = coroutine_handle<awaitable_frame>::from_promise(*this);
     return awaitable<T, Executor>(this);
-  };
+  }
 
   template <typename U>
   void return_value(U&& u)
@@ -583,7 +583,7 @@ class awaitable_frame<void, Executor>
   {
     this->coro_ = coroutine_handle<awaitable_frame>::from_promise(*this);
     return awaitable<void, Executor>(this);
-  };
+  }
 
   void return_void()
   {
@@ -621,7 +621,7 @@ class awaitable_frame<awaitable_thread_entry_point, Executor>
   {
     this->coro_ = coroutine_handle<awaitable_frame>::from_promise(*this);
     return awaitable<awaitable_thread_entry_point, Executor>(this);
-  };
+  }
 
   void return_void()
   {
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/cancel_after.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/cancel_after.hpp
new file mode 100644
index 0000000000..1a89a55892
--- /dev/null
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/cancel_after.hpp
@@ -0,0 +1,270 @@
+//
+// impl/cancel_after.hpp
+// ~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_IMPL_CANCEL_AFTER_HPP
+#define BOOST_ASIO_IMPL_CANCEL_AFTER_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/associated_executor.hpp>
+#include <boost/asio/async_result.hpp>
+#include <boost/asio/detail/initiation_base.hpp>
+#include <boost/asio/detail/timed_cancel_op.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename Initiation, typename Clock,
+    typename WaitTraits, typename... Signatures>
+struct initiate_cancel_after : initiation_base<Initiation>
+{
+  using initiation_base<Initiation>::initiation_base;
+
+  template <typename Handler, typename Rep, typename Period, typename... Args>
+  void operator()(Handler&& handler,
+      const chrono::duration<Rep, Period>& timeout,
+      cancellation_type_t cancel_type, Args&&... args) &&
+  {
+    using op = detail::timed_cancel_op<decay_t<Handler>,
+        basic_waitable_timer<Clock, WaitTraits>, Signatures...>;
+
+    non_const_lvalue<Handler> handler2(handler);
+    typename op::ptr p = { boost::asio::detail::addressof(handler2.value),
+        op::ptr::allocate(handler2.value), 0 };
+    p.p = new (p.v) op(handler2.value,
+        basic_waitable_timer<Clock, WaitTraits,
+          typename Initiation::executor_type>(this->get_executor(), timeout),
+        cancel_type);
+
+    op* o = p.p;
+    p.v = p.p = 0;
+    o->start(static_cast<Initiation&&>(*this), static_cast<Args&&>(args)...);
+  }
+
+  template <typename Handler, typename Rep, typename Period, typename... Args>
+  void operator()(Handler&& handler,
+      const chrono::duration<Rep, Period>& timeout,
+      cancellation_type_t cancel_type, Args&&... args) const &
+  {
+    using op = detail::timed_cancel_op<decay_t<Handler>,
+        basic_waitable_timer<Clock, WaitTraits>, Signatures...>;
+
+    non_const_lvalue<Handler> handler2(handler);
+    typename op::ptr p = { boost::asio::detail::addressof(handler2.value),
+        op::ptr::allocate(handler2.value), 0 };
+    p.p = new (p.v) op(handler2.value,
+        basic_waitable_timer<Clock, WaitTraits,
+          typename Initiation::executor_type>(this->get_executor(), timeout),
+        cancel_type);
+
+    op* o = p.p;
+    p.v = p.p = 0;
+    o->start(static_cast<const Initiation&>(*this),
+        static_cast<Args&&>(args)...);
+  }
+};
+
+template <typename Initiation, typename Clock,
+    typename WaitTraits, typename Executor, typename... Signatures>
+struct initiate_cancel_after_timer : initiation_base<Initiation>
+{
+  using initiation_base<Initiation>::initiation_base;
+
+  template <typename Handler, typename Rep, typename Period, typename... Args>
+  void operator()(Handler&& handler,
+      basic_waitable_timer<Clock, WaitTraits, Executor>* timer,
+      const chrono::duration<Rep, Period>& timeout,
+      cancellation_type_t cancel_type, Args&&... args) &&
+  {
+    using op = detail::timed_cancel_op<decay_t<Handler>,
+        basic_waitable_timer<Clock, WaitTraits, Executor>&, Signatures...>;
+
+    non_const_lvalue<Handler> handler2(handler);
+    typename op::ptr p = { boost::asio::detail::addressof(handler2.value),
+        op::ptr::allocate(handler2.value), 0 };
+    timer->expires_after(timeout);
+    p.p = new (p.v) op(handler2.value, *timer, cancel_type);
+
+    op* o = p.p;
+    p.v = p.p = 0;
+    o->start(static_cast<Initiation&&>(*this), static_cast<Args&&>(args)...);
+  }
+
+  template <typename Handler, typename Rep, typename Period, typename... Args>
+  void operator()(Handler&& handler,
+      basic_waitable_timer<Clock, WaitTraits, Executor>* timer,
+      const chrono::duration<Rep, Period>& timeout,
+      cancellation_type_t cancel_type, Args&&... args) const &
+  {
+    using op = detail::timed_cancel_op<decay_t<Handler>,
+        basic_waitable_timer<Clock, WaitTraits, Executor>&, Signatures...>;
+
+    non_const_lvalue<Handler> handler2(handler);
+    typename op::ptr p = { boost::asio::detail::addressof(handler2.value),
+        op::ptr::allocate(handler2.value), 0 };
+    timer->expires_after(timeout);
+    p.p = new (p.v) op(handler2.value, *timer, cancel_type);
+
+    op* o = p.p;
+    p.v = p.p = 0;
+    o->start(static_cast<const Initiation&>(*this),
+        static_cast<Args&&>(args)...);
+  }
+};
+
+} // namespace detail
+
+#if !defined(GENERATING_DOCUMENTATION)
+
+template <typename CompletionToken, typename Clock,
+    typename WaitTraits, typename... Signatures>
+struct async_result<
+    cancel_after_t<CompletionToken, Clock, WaitTraits>, Signatures...>
+  : async_result<CompletionToken, Signatures...>
+{
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static auto initiate(Initiation&& initiation,
+      RawCompletionToken&& token, Args&&... args)
+    -> decltype(
+      async_initiate<
+        conditional_t<
+          is_const<remove_reference_t<RawCompletionToken>>::value,
+            const CompletionToken, CompletionToken>,
+        Signatures...>(
+          declval<detail::initiate_cancel_after<
+            decay_t<Initiation>, Clock, WaitTraits, Signatures...>>(),
+          token.token_, token.timeout_, token.cancel_type_,
+          static_cast<Args&&>(args)...))
+  {
+    return async_initiate<
+      conditional_t<
+        is_const<remove_reference_t<RawCompletionToken>>::value,
+          const CompletionToken, CompletionToken>,
+      Signatures...>(
+        detail::initiate_cancel_after<
+          decay_t<Initiation>, Clock, WaitTraits, Signatures...>(
+            static_cast<Initiation&&>(initiation)),
+        token.token_, token.timeout_, token.cancel_type_,
+        static_cast<Args&&>(args)...);
+  }
+};
+
+template <typename CompletionToken, typename Clock,
+    typename WaitTraits, typename Executor, typename... Signatures>
+struct async_result<
+    cancel_after_timer<CompletionToken, Clock, WaitTraits, Executor>,
+    Signatures...>
+  : async_result<CompletionToken, Signatures...>
+{
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static auto initiate(Initiation&& initiation,
+      RawCompletionToken&& token, Args&&... args)
+    -> decltype(
+      async_initiate<
+        conditional_t<
+          is_const<remove_reference_t<RawCompletionToken>>::value,
+            const CompletionToken, CompletionToken>,
+        Signatures...>(
+          declval<detail::initiate_cancel_after_timer<
+            decay_t<Initiation>, Clock, WaitTraits, Executor, Signatures...>>(),
+          token.token_, &token.timer_, token.timeout_,
+          token.cancel_type_, static_cast<Args&&>(args)...))
+  {
+    return async_initiate<
+      conditional_t<
+        is_const<remove_reference_t<RawCompletionToken>>::value,
+          const CompletionToken, CompletionToken>,
+      Signatures...>(
+        detail::initiate_cancel_after_timer<
+          decay_t<Initiation>, Clock, WaitTraits, Executor, Signatures...>(
+            static_cast<Initiation&&>(initiation)),
+        token.token_, &token.timer_, token.timeout_,
+        token.cancel_type_, static_cast<Args&&>(args)...);
+  }
+};
+
+template <typename Clock, typename WaitTraits, typename... Signatures>
+struct async_result<partial_cancel_after<Clock, WaitTraits>, Signatures...>
+{
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static auto initiate(Initiation&& initiation,
+      RawCompletionToken&& token, Args&&... args)
+    -> decltype(
+      async_initiate<
+        const cancel_after_t<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          Clock, WaitTraits>&,
+        Signatures...>(
+          static_cast<Initiation&&>(initiation),
+          cancel_after_t<
+            default_completion_token_t<associated_executor_t<Initiation>>,
+            Clock, WaitTraits>(
+              default_completion_token_t<associated_executor_t<Initiation>>{},
+              token.timeout_, token.cancel_type_),
+          static_cast<Args&&>(args)...))
+  {
+    return async_initiate<
+      const cancel_after_t<
+        default_completion_token_t<associated_executor_t<Initiation>>,
+        Clock, WaitTraits>&,
+      Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        cancel_after_t<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          Clock, WaitTraits>(
+            default_completion_token_t<associated_executor_t<Initiation>>{},
+            token.timeout_, token.cancel_type_),
+        static_cast<Args&&>(args)...);
+  }
+};
+
+template <typename Clock, typename WaitTraits,
+    typename Executor, typename... Signatures>
+struct async_result<
+    partial_cancel_after_timer<Clock, WaitTraits, Executor>, Signatures...>
+{
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static auto initiate(Initiation&& initiation,
+      RawCompletionToken&& token, Args&&... args)
+    -> decltype(
+      async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        cancel_after_timer<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          Clock, WaitTraits, Executor>(
+            default_completion_token_t<associated_executor_t<Initiation>>{},
+            token.timer_, token.timeout_, token.cancel_type_),
+        static_cast<Args&&>(args)...))
+  {
+    return async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        cancel_after_timer<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          Clock, WaitTraits, Executor>(
+            default_completion_token_t<associated_executor_t<Initiation>>{},
+            token.timer_, token.timeout_, token.cancel_type_),
+        static_cast<Args&&>(args)...);
+  }
+};
+
+#endif // !defined(GENERATING_DOCUMENTATION)
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_IMPL_CANCEL_AFTER_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/cancel_at.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/cancel_at.hpp
new file mode 100644
index 0000000000..7634b5da03
--- /dev/null
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/cancel_at.hpp
@@ -0,0 +1,270 @@
+//
+// impl/cancel_at.hpp
+// ~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_ASIO_IMPL_CANCEL_AT_HPP
+#define BOOST_ASIO_IMPL_CANCEL_AT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/associated_executor.hpp>
+#include <boost/asio/async_result.hpp>
+#include <boost/asio/detail/initiation_base.hpp>
+#include <boost/asio/detail/timed_cancel_op.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename Initiation, typename Clock,
+    typename WaitTraits, typename... Signatures>
+struct initiate_cancel_at : initiation_base<Initiation>
+{
+  using initiation_base<Initiation>::initiation_base;
+
+  template <typename Handler, typename Duration, typename... Args>
+  void operator()(Handler&& handler,
+      const chrono::time_point<Clock, Duration>& expiry,
+      cancellation_type_t cancel_type, Args&&... args) &&
+  {
+    using op = detail::timed_cancel_op<decay_t<Handler>,
+        basic_waitable_timer<Clock, WaitTraits>, Signatures...>;
+
+    non_const_lvalue<Handler> handler2(handler);
+    typename op::ptr p = { boost::asio::detail::addressof(handler2.value),
+        op::ptr::allocate(handler2.value), 0 };
+    p.p = new (p.v) op(handler2.value,
+        basic_waitable_timer<Clock, WaitTraits,
+          typename Initiation::executor_type>(this->get_executor(), expiry),
+        cancel_type);
+
+    op* o = p.p;
+    p.v = p.p = 0;
+    o->start(static_cast<Initiation&&>(*this), static_cast<Args&&>(args)...);
+  }
+
+  template <typename Handler, typename Duration, typename... Args>
+  void operator()(Handler&& handler,
+      const chrono::time_point<Clock, Duration>& expiry,
+      cancellation_type_t cancel_type, Args&&... args) const &
+  {
+    using op = detail::timed_cancel_op<decay_t<Handler>,
+        basic_waitable_timer<Clock, WaitTraits>, Signatures...>;
+
+    non_const_lvalue<Handler> handler2(handler);
+    typename op::ptr p = { boost::asio::detail::addressof(handler2.value),
+        op::ptr::allocate(handler2.value), 0 };
+    p.p = new (p.v) op(handler2.value,
+        basic_waitable_timer<Clock, WaitTraits,
+          typename Initiation::executor_type>(this->get_executor(), expiry),
+        cancel_type);
+
+    op* o = p.p;
+    p.v = p.p = 0;
+    o->start(static_cast<const Initiation&>(*this),
+        static_cast<Args&&>(args)...);
+  }
+};
+
+template <typename Initiation, typename Clock,
+    typename WaitTraits, typename Executor, typename... Signatures>
+struct initiate_cancel_at_timer : initiation_base<Initiation>
+{
+  using initiation_base<Initiation>::initiation_base;
+
+  template <typename Handler, typename Duration, typename... Args>
+  void operator()(Handler&& handler,
+      basic_waitable_timer<Clock, WaitTraits, Executor>* timer,
+      const chrono::time_point<Clock, Duration>& expiry,
+      cancellation_type_t cancel_type, Args&&... args) &&
+  {
+    using op = detail::timed_cancel_op<decay_t<Handler>,
+        basic_waitable_timer<Clock, WaitTraits, Executor>&, Signatures...>;
+
+    non_const_lvalue<Handler> handler2(handler);
+    typename op::ptr p = { boost::asio::detail::addressof(handler2.value),
+        op::ptr::allocate(handler2.value), 0 };
+    timer->expires_at(expiry);
+    p.p = new (p.v) op(handler2.value, *timer, cancel_type);
+
+    op* o = p.p;
+    p.v = p.p = 0;
+    o->start(static_cast<Initiation&&>(*this), static_cast<Args&&>(args)...);
+  }
+
+  template <typename Handler, typename Duration, typename... Args>
+  void operator()(Handler&& handler,
+      basic_waitable_timer<Clock, WaitTraits, Executor>* timer,
+      const chrono::time_point<Clock, Duration>& expiry,
+      cancellation_type_t cancel_type, Args&&... args) const &
+  {
+    using op = detail::timed_cancel_op<decay_t<Handler>,
+        basic_waitable_timer<Clock, WaitTraits, Executor>&, Signatures...>;
+
+    non_const_lvalue<Handler> handler2(handler);
+    typename op::ptr p = { boost::asio::detail::addressof(handler2.value),
+        op::ptr::allocate(handler2.value), 0 };
+    timer->expires_at(expiry);
+    p.p = new (p.v) op(handler2.value, *timer, cancel_type);
+
+    op* o = p.p;
+    p.v = p.p = 0;
+    o->start(static_cast<const Initiation&>(*this),
+        static_cast<Args&&>(args)...);
+  }
+};
+
+} // namespace detail
+
+#if !defined(GENERATING_DOCUMENTATION)
+
+template <typename CompletionToken, typename Clock,
+    typename WaitTraits, typename... Signatures>
+struct async_result<
+    cancel_at_t<CompletionToken, Clock, WaitTraits>, Signatures...>
+  : async_result<CompletionToken, Signatures...>
+{
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static auto initiate(Initiation&& initiation,
+      RawCompletionToken&& token, Args&&... args)
+    -> decltype(
+      async_initiate<
+        conditional_t<
+          is_const<remove_reference_t<RawCompletionToken>>::value,
+            const CompletionToken, CompletionToken>,
+        Signatures...>(
+          declval<detail::initiate_cancel_at<
+            decay_t<Initiation>, Clock, WaitTraits, Signatures...>>(),
+          token.token_, token.expiry_, token.cancel_type_,
+          static_cast<Args&&>(args)...))
+  {
+    return async_initiate<
+      conditional_t<
+        is_const<remove_reference_t<RawCompletionToken>>::value,
+          const CompletionToken, CompletionToken>,
+      Signatures...>(
+        detail::initiate_cancel_at<
+          decay_t<Initiation>, Clock, WaitTraits, Signatures...>(
+            static_cast<Initiation&&>(initiation)),
+        token.token_, token.expiry_, token.cancel_type_,
+        static_cast<Args&&>(args)...);
+  }
+};
+
+template <typename CompletionToken, typename Clock,
+    typename WaitTraits, typename Executor, typename... Signatures>
+struct async_result<
+    cancel_at_timer<CompletionToken, Clock, WaitTraits, Executor>,
+    Signatures...>
+  : async_result<CompletionToken, Signatures...>
+{
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static auto initiate(Initiation&& initiation,
+      RawCompletionToken&& token, Args&&... args)
+    -> decltype(
+      async_initiate<
+        conditional_t<
+          is_const<remove_reference_t<RawCompletionToken>>::value,
+            const CompletionToken, CompletionToken>,
+        Signatures...>(
+          declval<detail::initiate_cancel_at_timer<
+            decay_t<Initiation>, Clock, WaitTraits, Executor, Signatures...>>(),
+          token.token_, &token.timer_, token.expiry_, token.cancel_type_,
+          static_cast<Args&&>(args)...))
+  {
+    return async_initiate<
+      conditional_t<
+        is_const<remove_reference_t<RawCompletionToken>>::value,
+          const CompletionToken, CompletionToken>,
+      Signatures...>(
+        detail::initiate_cancel_at_timer<
+          decay_t<Initiation>, Clock, WaitTraits, Executor, Signatures...>(
+            static_cast<Initiation&&>(initiation)),
+        token.token_, &token.timer_, token.expiry_, token.cancel_type_,
+        static_cast<Args&&>(args)...);
+  }
+};
+
+template <typename Clock, typename WaitTraits, typename... Signatures>
+struct async_result<partial_cancel_at<Clock, WaitTraits>, Signatures...>
+{
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static auto initiate(Initiation&& initiation,
+      RawCompletionToken&& token, Args&&... args)
+    -> decltype(
+      async_initiate<
+        const cancel_at_t<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          Clock, WaitTraits>&,
+        Signatures...>(
+          static_cast<Initiation&&>(initiation),
+          cancel_at_t<
+            default_completion_token_t<associated_executor_t<Initiation>>,
+            Clock, WaitTraits>(
+              default_completion_token_t<associated_executor_t<Initiation>>{},
+              token.expiry_, token.cancel_type_),
+          static_cast<Args&&>(args)...))
+  {
+    return async_initiate<
+      const cancel_at_t<
+        default_completion_token_t<associated_executor_t<Initiation>>,
+        Clock, WaitTraits>&,
+      Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        cancel_at_t<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          Clock, WaitTraits>(
+            default_completion_token_t<associated_executor_t<Initiation>>{},
+            token.expiry_, token.cancel_type_),
+        static_cast<Args&&>(args)...);
+  }
+};
+
+template <typename Clock, typename WaitTraits,
+    typename Executor, typename... Signatures>
+struct async_result<
+    partial_cancel_at_timer<Clock, WaitTraits, Executor>, Signatures...>
+{
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static auto initiate(Initiation&& initiation,
+      RawCompletionToken&& token, Args&&... args)
+    -> decltype(
+      async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        cancel_at_timer<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          Clock, WaitTraits, Executor>(
+            default_completion_token_t<associated_executor_t<Initiation>>{},
+            token.timer_, token.expiry_, token.cancel_type_),
+        static_cast<Args&&>(args)...))
+  {
+    return async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        cancel_at_timer<
+          default_completion_token_t<associated_executor_t<Initiation>>,
+          Clock, WaitTraits, Executor>(
+            default_completion_token_t<associated_executor_t<Initiation>>{},
+            token.timer_, token.expiry_, token.cancel_type_),
+        static_cast<Args&&>(args)...);
+  }
+};
+
+#endif // !defined(GENERATING_DOCUMENTATION)
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_IMPL_CANCEL_AT_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/co_spawn.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/co_spawn.hpp
index f2b5137f87..31d3311c00 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/impl/co_spawn.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/co_spawn.hpp
@@ -143,7 +143,9 @@ awaitable<awaitable_thread_entry_point, Executor> co_spawn_entry_point(
   (co_await awaitable_thread_has_context_switched{}) = false;
   std::exception_ptr e = nullptr;
   bool done = false;
+#if !defined(BOOST_ASIO_NO_EXCEPTIONS)
   try
+#endif // !defined(BOOST_ASIO_NO_EXCEPTIONS)
   {
     T t = co_await s.function();
 
@@ -164,6 +166,7 @@ awaitable<awaitable_thread_entry_point, Executor> co_spawn_entry_point(
 
     co_return;
   }
+#if !defined(BOOST_ASIO_NO_EXCEPTIONS)
   catch (...)
   {
     if (done)
@@ -171,6 +174,7 @@ awaitable<awaitable_thread_entry_point, Executor> co_spawn_entry_point(
 
     e = std::current_exception();
   }
+#endif // !defined(BOOST_ASIO_NO_EXCEPTIONS)
 
   bool switched = (co_await awaitable_thread_has_context_switched{});
   if (!switched)
@@ -194,14 +198,18 @@ awaitable<awaitable_thread_entry_point, Executor> co_spawn_entry_point(
 
   (co_await awaitable_thread_has_context_switched{}) = false;
   std::exception_ptr e = nullptr;
+#if !defined(BOOST_ASIO_NO_EXCEPTIONS)
   try
+#endif // !defined(BOOST_ASIO_NO_EXCEPTIONS)
   {
     co_await s.function();
   }
+#if !defined(BOOST_ASIO_NO_EXCEPTIONS)
   catch (...)
   {
     e = std::current_exception();
   }
+#endif // !defined(BOOST_ASIO_NO_EXCEPTIONS)
 
   bool switched = (co_await awaitable_thread_has_context_switched{});
   if (!switched)
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/connect.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/connect.hpp
index 29138f648b..ab06b04c88 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/impl/connect.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/connect.hpp
@@ -35,15 +35,6 @@ namespace asio {
 
 namespace detail
 {
-  struct default_connect_condition
-  {
-    template <typename Endpoint>
-    bool operator()(const boost::system::error_code&, const Endpoint&)
-    {
-      return true;
-    }
-  };
-
   template <typename Protocol, typename Iterator>
   inline typename Protocol::endpoint deref_connect_result(
       Iterator iter, boost::system::error_code& ec)
@@ -51,38 +42,15 @@ namespace detail
     return ec ? typename Protocol::endpoint() : *iter;
   }
 
-  template <typename T, typename Iterator>
-  struct legacy_connect_condition_helper : T
-  {
-    typedef char (*fallback_func_type)(...);
-    operator fallback_func_type() const;
-  };
-
-  template <typename R, typename Arg1, typename Arg2, typename Iterator>
-  struct legacy_connect_condition_helper<R (*)(Arg1, Arg2), Iterator>
-  {
-    R operator()(Arg1, Arg2) const;
-    char operator()(...) const;
-  };
-
-  template <typename T, typename Iterator>
-  struct is_legacy_connect_condition
-  {
-    static char asio_connect_condition_check(char);
-    static char (&asio_connect_condition_check(Iterator))[2];
-
-    static const bool value =
-      sizeof(asio_connect_condition_check(
-        (declval<legacy_connect_condition_helper<T, Iterator>>())(
-          declval<const boost::system::error_code>(),
-          declval<const Iterator>()))) != 1;
-  };
-
   template <typename ConnectCondition, typename Iterator>
   inline Iterator call_connect_condition(ConnectCondition& connect_condition,
       const boost::system::error_code& ec, Iterator next, Iterator end,
-      enable_if_t<is_legacy_connect_condition<
-        ConnectCondition, Iterator>::value>* = 0)
+      constraint_t<
+        is_same<
+          result_of_t<ConnectCondition(boost::system::error_code, Iterator)>,
+          Iterator
+        >::value
+      > = 0)
   {
     if (next != end)
       return connect_condition(ec, next);
@@ -92,20 +60,27 @@ namespace detail
   template <typename ConnectCondition, typename Iterator>
   inline Iterator call_connect_condition(ConnectCondition& connect_condition,
       const boost::system::error_code& ec, Iterator next, Iterator end,
-      enable_if_t<!is_legacy_connect_condition<
-        ConnectCondition, Iterator>::value>* = 0)
+      constraint_t<
+        is_same<
+          result_of_t<ConnectCondition(boost::system::error_code,
+            decltype(*declval<Iterator>()))>,
+          bool
+        >::value
+      > = 0)
   {
     for (;next != end; ++next)
       if (connect_condition(ec, *next))
         return next;
     return end;
   }
-}
+} // namespace detail
 
 template <typename Protocol, typename Executor, typename EndpointSequence>
 typename Protocol::endpoint connect(basic_socket<Protocol, Executor>& s,
     const EndpointSequence& endpoints,
-    constraint_t<is_endpoint_sequence<EndpointSequence>::value>)
+    constraint_t<
+      is_endpoint_sequence<EndpointSequence>::value
+    >)
 {
   boost::system::error_code ec;
   typename Protocol::endpoint result = connect(s, endpoints, ec);
@@ -116,7 +91,9 @@ typename Protocol::endpoint connect(basic_socket<Protocol, Executor>& s,
 template <typename Protocol, typename Executor, typename EndpointSequence>
 typename Protocol::endpoint connect(basic_socket<Protocol, Executor>& s,
     const EndpointSequence& endpoints, boost::system::error_code& ec,
-    constraint_t<is_endpoint_sequence<EndpointSequence>::value>)
+    constraint_t<
+      is_endpoint_sequence<EndpointSequence>::value
+    >)
 {
   return detail::deref_connect_result<Protocol>(
       connect(s, endpoints.begin(), endpoints.end(),
@@ -126,7 +103,9 @@ typename Protocol::endpoint connect(basic_socket<Protocol, Executor>& s,
 #if !defined(BOOST_ASIO_NO_DEPRECATED)
 template <typename Protocol, typename Executor, typename Iterator>
 Iterator connect(basic_socket<Protocol, Executor>& s, Iterator begin,
-    constraint_t<!is_endpoint_sequence<Iterator>::value>)
+    constraint_t<
+      !is_endpoint_sequence<Iterator>::value
+    >)
 {
   boost::system::error_code ec;
   Iterator result = connect(s, begin, ec);
@@ -137,7 +116,9 @@ Iterator connect(basic_socket<Protocol, Executor>& s, Iterator begin,
 template <typename Protocol, typename Executor, typename Iterator>
 inline Iterator connect(basic_socket<Protocol, Executor>& s,
     Iterator begin, boost::system::error_code& ec,
-    constraint_t<!is_endpoint_sequence<Iterator>::value>)
+    constraint_t<
+      !is_endpoint_sequence<Iterator>::value
+    >)
 {
   return connect(s, begin, Iterator(), detail::default_connect_condition(), ec);
 }
@@ -164,7 +145,13 @@ template <typename Protocol, typename Executor,
     typename EndpointSequence, typename ConnectCondition>
 typename Protocol::endpoint connect(basic_socket<Protocol, Executor>& s,
     const EndpointSequence& endpoints, ConnectCondition connect_condition,
-    constraint_t<is_endpoint_sequence<EndpointSequence>::value>)
+    constraint_t<
+      is_endpoint_sequence<EndpointSequence>::value
+    >,
+    constraint_t<
+      is_connect_condition<ConnectCondition,
+        decltype(declval<const EndpointSequence&>().begin())>::value
+    >)
 {
   boost::system::error_code ec;
   typename Protocol::endpoint result = connect(
@@ -178,7 +165,13 @@ template <typename Protocol, typename Executor,
 typename Protocol::endpoint connect(basic_socket<Protocol, Executor>& s,
     const EndpointSequence& endpoints, ConnectCondition connect_condition,
     boost::system::error_code& ec,
-    constraint_t<is_endpoint_sequence<EndpointSequence>::value>)
+    constraint_t<
+      is_endpoint_sequence<EndpointSequence>::value
+    >,
+    constraint_t<
+      is_connect_condition<ConnectCondition,
+        decltype(declval<const EndpointSequence&>().begin())>::value
+    >)
 {
   return detail::deref_connect_result<Protocol>(
       connect(s, endpoints.begin(), endpoints.end(),
@@ -190,7 +183,12 @@ template <typename Protocol, typename Executor,
     typename Iterator, typename ConnectCondition>
 Iterator connect(basic_socket<Protocol, Executor>& s,
     Iterator begin, ConnectCondition connect_condition,
-    constraint_t<!is_endpoint_sequence<Iterator>::value>)
+    constraint_t<
+      !is_endpoint_sequence<Iterator>::value
+    >,
+    constraint_t<
+      is_connect_condition<ConnectCondition, Iterator>::value
+    >)
 {
   boost::system::error_code ec;
   Iterator result = connect(s, begin, connect_condition, ec);
@@ -203,7 +201,12 @@ template <typename Protocol, typename Executor,
 inline Iterator connect(basic_socket<Protocol, Executor>& s,
     Iterator begin, ConnectCondition connect_condition,
     boost::system::error_code& ec,
-    constraint_t<!is_endpoint_sequence<Iterator>::value>)
+    constraint_t<
+      !is_endpoint_sequence<Iterator>::value
+    >,
+    constraint_t<
+      is_connect_condition<ConnectCondition, Iterator>::value
+    >)
 {
   return connect(s, begin, Iterator(), connect_condition, ec);
 }
@@ -212,7 +215,10 @@ inline Iterator connect(basic_socket<Protocol, Executor>& s,
 template <typename Protocol, typename Executor,
     typename Iterator, typename ConnectCondition>
 Iterator connect(basic_socket<Protocol, Executor>& s, Iterator begin,
-    Iterator end, ConnectCondition connect_condition)
+    Iterator end, ConnectCondition connect_condition,
+    constraint_t<
+      is_connect_condition<ConnectCondition, Iterator>::value
+    >)
 {
   boost::system::error_code ec;
   Iterator result = connect(s, begin, end, connect_condition, ec);
@@ -224,7 +230,10 @@ template <typename Protocol, typename Executor,
     typename Iterator, typename ConnectCondition>
 Iterator connect(basic_socket<Protocol, Executor>& s, Iterator begin,
     Iterator end, ConnectCondition connect_condition,
-    boost::system::error_code& ec)
+    boost::system::error_code& ec,
+    constraint_t<
+      is_connect_condition<ConnectCondition, Iterator>::value
+    >)
 {
   ec = boost::system::error_code();
 
@@ -688,121 +697,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename Protocol, typename Executor, typename EndpointSequence,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      typename Protocol::endpoint)) RangeConnectToken>
-inline auto async_connect(basic_socket<Protocol, Executor>& s,
-    const EndpointSequence& endpoints, RangeConnectToken&& token,
-    constraint_t<is_endpoint_sequence<EndpointSequence>::value>)
-  -> decltype(
-    async_initiate<RangeConnectToken,
-      void (boost::system::error_code, typename Protocol::endpoint)>(
-        declval<detail::initiate_async_range_connect<Protocol, Executor>>(),
-        token, endpoints, declval<detail::default_connect_condition>()))
-{
-  return async_initiate<RangeConnectToken,
-    void (boost::system::error_code, typename Protocol::endpoint)>(
-      detail::initiate_async_range_connect<Protocol, Executor>(s),
-      token, endpoints, detail::default_connect_condition());
-}
-
-#if !defined(BOOST_ASIO_NO_DEPRECATED)
-template <typename Protocol, typename Executor, typename Iterator,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      Iterator)) IteratorConnectToken>
-inline auto async_connect(basic_socket<Protocol, Executor>& s,
-    Iterator begin, IteratorConnectToken&& token,
-    constraint_t<!is_endpoint_sequence<Iterator>::value>)
-  -> decltype(
-    async_initiate<IteratorConnectToken,
-      void (boost::system::error_code, Iterator)>(
-        declval<detail::initiate_async_iterator_connect<Protocol, Executor>>(),
-        token, begin, Iterator(), declval<detail::default_connect_condition>()))
-{
-  return async_initiate<IteratorConnectToken,
-    void (boost::system::error_code, Iterator)>(
-      detail::initiate_async_iterator_connect<Protocol, Executor>(s),
-      token, begin, Iterator(), detail::default_connect_condition());
-}
-#endif // !defined(BOOST_ASIO_NO_DEPRECATED)
-
-template <typename Protocol, typename Executor, typename Iterator,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      Iterator)) IteratorConnectToken>
-inline auto async_connect(basic_socket<Protocol, Executor>& s,
-    Iterator begin, Iterator end, IteratorConnectToken&& token)
-  -> decltype(
-    async_initiate<IteratorConnectToken,
-      void (boost::system::error_code, Iterator)>(
-        declval<detail::initiate_async_iterator_connect<Protocol, Executor>>(),
-        token, begin, end, declval<detail::default_connect_condition>()))
-{
-  return async_initiate<IteratorConnectToken,
-    void (boost::system::error_code, Iterator)>(
-      detail::initiate_async_iterator_connect<Protocol, Executor>(s),
-      token, begin, end, detail::default_connect_condition());
-}
-
-template <typename Protocol, typename Executor,
-    typename EndpointSequence, typename ConnectCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      typename Protocol::endpoint)) RangeConnectToken>
-inline auto async_connect(basic_socket<Protocol, Executor>& s,
-    const EndpointSequence& endpoints, ConnectCondition connect_condition,
-    RangeConnectToken&& token,
-    constraint_t<is_endpoint_sequence<EndpointSequence>::value>)
-  -> decltype(
-    async_initiate<RangeConnectToken,
-      void (boost::system::error_code, typename Protocol::endpoint)>(
-        declval<detail::initiate_async_range_connect<Protocol, Executor>>(),
-        token, endpoints, connect_condition))
-{
-  return async_initiate<RangeConnectToken,
-    void (boost::system::error_code, typename Protocol::endpoint)>(
-      detail::initiate_async_range_connect<Protocol, Executor>(s),
-      token, endpoints, connect_condition);
-}
-
-#if !defined(BOOST_ASIO_NO_DEPRECATED)
-template <typename Protocol, typename Executor,
-    typename Iterator, typename ConnectCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      Iterator)) IteratorConnectToken>
-inline auto async_connect(basic_socket<Protocol, Executor>& s, Iterator begin,
-    ConnectCondition connect_condition, IteratorConnectToken&& token,
-    constraint_t<!is_endpoint_sequence<Iterator>::value>)
-  -> decltype(
-    async_initiate<IteratorConnectToken,
-      void (boost::system::error_code, Iterator)>(
-        declval<detail::initiate_async_iterator_connect<Protocol, Executor>>(),
-        token, begin, Iterator(), connect_condition))
-{
-  return async_initiate<IteratorConnectToken,
-    void (boost::system::error_code, Iterator)>(
-      detail::initiate_async_iterator_connect<Protocol, Executor>(s),
-      token, begin, Iterator(), connect_condition);
-}
-#endif // !defined(BOOST_ASIO_NO_DEPRECATED)
-
-template <typename Protocol, typename Executor,
-    typename Iterator, typename ConnectCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      Iterator)) IteratorConnectToken>
-inline auto async_connect(basic_socket<Protocol, Executor>& s,
-    Iterator begin, Iterator end, ConnectCondition connect_condition,
-    IteratorConnectToken&& token)
-  -> decltype(
-    async_initiate<IteratorConnectToken,
-      void (boost::system::error_code, Iterator)>(
-        declval<detail::initiate_async_iterator_connect<Protocol, Executor>>(),
-        token, begin, end, connect_condition))
-{
-  return async_initiate<IteratorConnectToken,
-    void (boost::system::error_code, Iterator)>(
-      detail::initiate_async_iterator_connect<Protocol, Executor>(s),
-      token, begin, end, connect_condition);
-}
-
 } // namespace asio
 } // namespace boost
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/consign.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/consign.hpp
index 59e977d545..03942963c6 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/impl/consign.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/consign.hpp
@@ -19,6 +19,7 @@
 #include <boost/asio/associator.hpp>
 #include <boost/asio/async_result.hpp>
 #include <boost/asio/detail/handler_cont_helpers.hpp>
+#include <boost/asio/detail/initiation_base.hpp>
 #include <boost/asio/detail/type_traits.hpp>
 #include <boost/asio/detail/utility.hpp>
 
@@ -70,25 +71,31 @@ struct async_result<consign_t<CompletionToken, Values...>, Signatures...>
   : async_result<CompletionToken, Signatures...>
 {
   template <typename Initiation>
-  struct init_wrapper
+  struct init_wrapper : detail::initiation_base<Initiation>
   {
-    init_wrapper(Initiation init)
-      : initiation_(static_cast<Initiation&&>(init))
+    using detail::initiation_base<Initiation>::initiation_base;
+
+    template <typename Handler, typename... Args>
+    void operator()(Handler&& handler,
+        std::tuple<Values...> values, Args&&... args) &&
     {
+      static_cast<Initiation&&>(*this)(
+          detail::consign_handler<decay_t<Handler>, Values...>(
+            static_cast<Handler&&>(handler),
+            static_cast<std::tuple<Values...>&&>(values)),
+          static_cast<Args&&>(args)...);
     }
 
     template <typename Handler, typename... Args>
     void operator()(Handler&& handler,
-        std::tuple<Values...> values, Args&&... args)
+        std::tuple<Values...> values, Args&&... args) const &
     {
-      static_cast<Initiation&&>(initiation_)(
+      static_cast<const Initiation&>(*this)(
           detail::consign_handler<decay_t<Handler>, Values...>(
             static_cast<Handler&&>(handler),
             static_cast<std::tuple<Values...>&&>(values)),
           static_cast<Args&&>(args)...);
     }
-
-    Initiation initiation_;
   };
 
   template <typename Initiation, typename RawCompletionToken, typename... Args>
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/detached.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/detached.hpp
index 8fdcfc6d54..2ad31cb29b 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/impl/detached.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/detached.hpp
@@ -44,8 +44,8 @@ namespace detail {
 
 #if !defined(GENERATING_DOCUMENTATION)
 
-template <typename Signature>
-struct async_result<detached_t, Signature>
+template <typename... Signatures>
+struct async_result<detached_t, Signatures...>
 {
   typedef boost::asio::detail::detached_handler completion_handler_type;
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/prepend.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/prepend.hpp
index 841fb89094..7db1bf2f1b 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/impl/prepend.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/prepend.hpp
@@ -19,6 +19,7 @@
 #include <boost/asio/associator.hpp>
 #include <boost/asio/async_result.hpp>
 #include <boost/asio/detail/handler_cont_helpers.hpp>
+#include <boost/asio/detail/initiation_base.hpp>
 #include <boost/asio/detail/type_traits.hpp>
 #include <boost/asio/detail/utility.hpp>
 
@@ -95,25 +96,31 @@ struct async_result<
       Signature, Values...>::type signature;
 
   template <typename Initiation>
-  struct init_wrapper
+  struct init_wrapper : detail::initiation_base<Initiation>
   {
-    init_wrapper(Initiation init)
-      : initiation_(static_cast<Initiation&&>(init))
+    using detail::initiation_base<Initiation>::initiation_base;
+
+    template <typename Handler, typename... Args>
+    void operator()(Handler&& handler,
+        std::tuple<Values...> values, Args&&... args) &&
     {
+      static_cast<Initiation&&>(*this)(
+          detail::prepend_handler<decay_t<Handler>, Values...>(
+            static_cast<Handler&&>(handler),
+            static_cast<std::tuple<Values...>&&>(values)),
+          static_cast<Args&&>(args)...);
     }
 
     template <typename Handler, typename... Args>
     void operator()(Handler&& handler,
-        std::tuple<Values...> values, Args&&... args)
+        std::tuple<Values...> values, Args&&... args) const &
     {
-      static_cast<Initiation&&>(initiation_)(
+      static_cast<const Initiation&>(*this)(
           detail::prepend_handler<decay_t<Handler>, Values...>(
             static_cast<Handler&&>(handler),
             static_cast<std::tuple<Values...>&&>(values)),
           static_cast<Args&&>(args)...);
     }
-
-    Initiation initiation_;
   };
 
   template <typename Initiation, typename RawCompletionToken, typename... Args>
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/read.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/read.hpp
index 2846587398..9b05a671fb 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/impl/read.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/read.hpp
@@ -65,6 +65,9 @@ std::size_t read(SyncReadStream& s, const MutableBufferSequence& buffers,
     CompletionCondition completion_condition, boost::system::error_code& ec,
     constraint_t<
       is_mutable_buffer_sequence<MutableBufferSequence>::value
+    >,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     >)
 {
   return detail::read_buffer_seq(s, buffers,
@@ -100,6 +103,9 @@ inline std::size_t read(SyncReadStream& s, const MutableBufferSequence& buffers,
     CompletionCondition completion_condition,
     constraint_t<
       is_mutable_buffer_sequence<MutableBufferSequence>::value
+    >,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     >)
 {
   boost::system::error_code ec;
@@ -121,6 +127,9 @@ std::size_t read(SyncReadStream& s,
     >,
     constraint_t<
       !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
+    >,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     >)
 {
   decay_t<DynamicBuffer_v1> b(
@@ -189,6 +198,9 @@ inline std::size_t read(SyncReadStream& s,
     >,
     constraint_t<
       !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
+    >,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     >)
 {
   boost::system::error_code ec;
@@ -206,7 +218,10 @@ template <typename SyncReadStream, typename Allocator,
     typename CompletionCondition>
 inline std::size_t read(SyncReadStream& s,
     boost::asio::basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition, boost::system::error_code& ec)
+    CompletionCondition completion_condition, boost::system::error_code& ec,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    >)
 {
   return read(s, basic_streambuf_ref<Allocator>(b),
       static_cast<CompletionCondition&&>(completion_condition), ec);
@@ -231,7 +246,10 @@ template <typename SyncReadStream, typename Allocator,
     typename CompletionCondition>
 inline std::size_t read(SyncReadStream& s,
     boost::asio::basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition)
+    CompletionCondition completion_condition,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    >)
 {
   return read(s, basic_streambuf_ref<Allocator>(b),
       static_cast<CompletionCondition&&>(completion_condition));
@@ -247,6 +265,9 @@ std::size_t read(SyncReadStream& s, DynamicBuffer_v2 buffers,
     CompletionCondition completion_condition, boost::system::error_code& ec,
     constraint_t<
       is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+    >,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     >)
 {
   DynamicBuffer_v2& b = buffers;
@@ -305,6 +326,9 @@ inline std::size_t read(SyncReadStream& s, DynamicBuffer_v2 buffers,
     CompletionCondition completion_condition,
     constraint_t<
       is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+    >,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     >)
 {
   boost::system::error_code ec;
@@ -498,47 +522,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncReadStream,
-    typename MutableBufferSequence, typename CompletionCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read(AsyncReadStream& s, const MutableBufferSequence& buffers,
-    CompletionCondition completion_condition, ReadToken&& token,
-    constraint_t<
-      is_mutable_buffer_sequence<MutableBufferSequence>::value
-    >)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read<AsyncReadStream>>(), token, buffers,
-        static_cast<CompletionCondition&&>(completion_condition)))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read<AsyncReadStream>(s), token, buffers,
-      static_cast<CompletionCondition&&>(completion_condition));
-}
-
-template <typename AsyncReadStream, typename MutableBufferSequence,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read(AsyncReadStream& s,
-    const MutableBufferSequence& buffers, ReadToken&& token,
-    constraint_t<
-      is_mutable_buffer_sequence<MutableBufferSequence>::value
-    >)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read<AsyncReadStream>>(),
-        token, buffers, transfer_all()))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read<AsyncReadStream>(s),
-      token, buffers, transfer_all());
-}
-
 #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1)
 
 namespace detail
@@ -723,97 +706,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncReadStream, typename DynamicBuffer_v1,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read(AsyncReadStream& s,
-    DynamicBuffer_v1&& buffers, ReadToken&& token,
-    constraint_t<
-      is_dynamic_buffer_v1<decay_t<DynamicBuffer_v1>>::value
-    >,
-    constraint_t<
-      !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
-    >)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_dynbuf_v1<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v1&&>(buffers), transfer_all()))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_dynbuf_v1<AsyncReadStream>(s),
-      token, static_cast<DynamicBuffer_v1&&>(buffers), transfer_all());
-}
-
-template <typename AsyncReadStream,
-    typename DynamicBuffer_v1, typename CompletionCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
-    CompletionCondition completion_condition, ReadToken&& token,
-    constraint_t<
-      is_dynamic_buffer_v1<decay_t<DynamicBuffer_v1>>::value
-    >,
-    constraint_t<
-      !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
-    >)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_dynbuf_v1<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v1&&>(buffers),
-        static_cast<CompletionCondition&&>(completion_condition)))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_dynbuf_v1<AsyncReadStream>(s),
-      token, static_cast<DynamicBuffer_v1&&>(buffers),
-      static_cast<CompletionCondition&&>(completion_condition));
-}
-
-#if !defined(BOOST_ASIO_NO_EXTENSIONS)
-#if !defined(BOOST_ASIO_NO_IOSTREAM)
-
-template <typename AsyncReadStream, typename Allocator,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read(AsyncReadStream& s,
-    basic_streambuf<Allocator>& b, ReadToken&& token)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_dynbuf_v1<AsyncReadStream>>(),
-        token, basic_streambuf_ref<Allocator>(b), transfer_all()))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_dynbuf_v1<AsyncReadStream>(s),
-      token, basic_streambuf_ref<Allocator>(b), transfer_all());
-}
-
-template <typename AsyncReadStream,
-    typename Allocator, typename CompletionCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read(AsyncReadStream& s, basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition, ReadToken&& token)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_dynbuf_v1<AsyncReadStream>>(),
-        token, basic_streambuf_ref<Allocator>(b),
-        static_cast<CompletionCondition&&>(completion_condition)))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_dynbuf_v1<AsyncReadStream>(s),
-      token, basic_streambuf_ref<Allocator>(b),
-      static_cast<CompletionCondition&&>(completion_condition));
-}
-
-#endif // !defined(BOOST_ASIO_NO_IOSTREAM)
-#endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
 #endif // !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1)
 
 namespace detail
@@ -1004,49 +896,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncReadStream, typename DynamicBuffer_v2,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read(AsyncReadStream& s,
-    DynamicBuffer_v2 buffers, ReadToken&& token,
-    constraint_t<
-      is_dynamic_buffer_v2<DynamicBuffer_v2>::value
-    >)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_dynbuf_v2<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v2&&>(buffers), transfer_all()))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_dynbuf_v2<AsyncReadStream>(s),
-      token, static_cast<DynamicBuffer_v2&&>(buffers), transfer_all());
-}
-
-template <typename AsyncReadStream,
-    typename DynamicBuffer_v2, typename CompletionCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read(AsyncReadStream& s, DynamicBuffer_v2 buffers,
-    CompletionCondition completion_condition, ReadToken&& token,
-    constraint_t<
-      is_dynamic_buffer_v2<DynamicBuffer_v2>::value
-    >)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_dynbuf_v2<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v2&&>(buffers),
-        static_cast<CompletionCondition&&>(completion_condition)))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_dynbuf_v2<AsyncReadStream>(s),
-      token, static_cast<DynamicBuffer_v2&&>(buffers),
-      static_cast<CompletionCondition&&>(completion_condition));
-}
-
 } // namespace asio
 } // namespace boost
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/read_at.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/read_at.hpp
index 77246f39c7..44cc717d3d 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/impl/read_at.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/read_at.hpp
@@ -67,7 +67,10 @@ template <typename SyncRandomAccessReadDevice, typename MutableBufferSequence,
     typename CompletionCondition>
 std::size_t read_at(SyncRandomAccessReadDevice& d,
     uint64_t offset, const MutableBufferSequence& buffers,
-    CompletionCondition completion_condition, boost::system::error_code& ec)
+    CompletionCondition completion_condition, boost::system::error_code& ec,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    >)
 {
   return detail::read_at_buffer_sequence(d, offset, buffers,
       boost::asio::buffer_sequence_begin(buffers),
@@ -97,7 +100,10 @@ template <typename SyncRandomAccessReadDevice, typename MutableBufferSequence,
     typename CompletionCondition>
 inline std::size_t read_at(SyncRandomAccessReadDevice& d,
     uint64_t offset, const MutableBufferSequence& buffers,
-    CompletionCondition completion_condition)
+    CompletionCondition completion_condition,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    >)
 {
   boost::system::error_code ec;
   std::size_t bytes_transferred = read_at(d, offset, buffers,
@@ -113,7 +119,10 @@ template <typename SyncRandomAccessReadDevice, typename Allocator,
     typename CompletionCondition>
 std::size_t read_at(SyncRandomAccessReadDevice& d,
     uint64_t offset, boost::asio::basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition, boost::system::error_code& ec)
+    CompletionCondition completion_condition, boost::system::error_code& ec,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    >)
 {
   ec = boost::system::error_code();
   std::size_t total_transferred = 0;
@@ -156,7 +165,10 @@ template <typename SyncRandomAccessReadDevice, typename Allocator,
     typename CompletionCondition>
 inline std::size_t read_at(SyncRandomAccessReadDevice& d,
     uint64_t offset, boost::asio::basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition)
+    CompletionCondition completion_condition,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    >)
 {
   boost::system::error_code ec;
   std::size_t bytes_transferred = read_at(d, offset, b,
@@ -360,44 +372,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncRandomAccessReadDevice,
-    typename MutableBufferSequence, typename CompletionCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_at(AsyncRandomAccessReadDevice& d,
-    uint64_t offset, const MutableBufferSequence& buffers,
-    CompletionCondition completion_condition, ReadToken&& token)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_at<AsyncRandomAccessReadDevice>>(),
-        token, offset, buffers,
-        static_cast<CompletionCondition&&>(completion_condition)))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_at<AsyncRandomAccessReadDevice>(d),
-      token, offset, buffers,
-      static_cast<CompletionCondition&&>(completion_condition));
-}
-
-template <typename AsyncRandomAccessReadDevice, typename MutableBufferSequence,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_at(AsyncRandomAccessReadDevice& d,
-    uint64_t offset, const MutableBufferSequence& buffers, ReadToken&& token)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_at<AsyncRandomAccessReadDevice>>(),
-        token, offset, buffers, transfer_all()))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_at<AsyncRandomAccessReadDevice>(d),
-      token, offset, buffers, transfer_all());
-}
-
 #if !defined(BOOST_ASIO_NO_EXTENSIONS)
 #if !defined(BOOST_ASIO_NO_IOSTREAM)
 
@@ -579,46 +553,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncRandomAccessReadDevice,
-    typename Allocator, typename CompletionCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_at(AsyncRandomAccessReadDevice& d,
-    uint64_t offset, boost::asio::basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition, ReadToken&& token)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_at_streambuf<
-          AsyncRandomAccessReadDevice>>(),
-        token, offset, &b,
-        static_cast<CompletionCondition&&>(completion_condition)))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_at_streambuf<AsyncRandomAccessReadDevice>(d),
-      token, offset, &b,
-      static_cast<CompletionCondition&&>(completion_condition));
-}
-
-template <typename AsyncRandomAccessReadDevice, typename Allocator,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_at(AsyncRandomAccessReadDevice& d, uint64_t offset,
-    boost::asio::basic_streambuf<Allocator>& b, ReadToken&& token)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_at_streambuf<
-          AsyncRandomAccessReadDevice>>(),
-        token, offset, &b, transfer_all()))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_at_streambuf<AsyncRandomAccessReadDevice>(d),
-      token, offset, &b, transfer_all());
-}
-
 #endif // !defined(BOOST_ASIO_NO_IOSTREAM)
 #endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/read_until.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/read_until.hpp
index 322c9d1d86..08e51ecc48 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/impl/read_until.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/read_until.hpp
@@ -69,6 +69,19 @@ namespace detail
     }
     return std::make_pair(last1, false);
   }
+
+#if !defined(BOOST_ASIO_NO_EXTENSIONS)
+#if defined(BOOST_ASIO_HAS_BOOST_REGEX)
+  struct regex_match_flags
+  {
+    template <typename T>
+    operator T() const
+    {
+      return T::match_default | T::match_partial;
+    }
+  };
+#endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
+#endif // defined(BOOST_ASIO_HAS_BOOST_REGEX)
 } // namespace detail
 
 #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1)
@@ -232,19 +245,6 @@ std::size_t read_until(SyncReadStream& s,
 #if !defined(BOOST_ASIO_NO_EXTENSIONS)
 #if defined(BOOST_ASIO_HAS_BOOST_REGEX)
 
-namespace detail {
-
-struct regex_match_flags
-{
-  template <typename T>
-  operator T() const
-  {
-    return T::match_default | T::match_partial;
-  }
-};
-
-} // namespace detail
-
 template <typename SyncReadStream, typename DynamicBuffer_v1, typename Traits>
 inline std::size_t read_until(SyncReadStream& s, DynamicBuffer_v1&& buffers,
     const boost::basic_regex<char, Traits>& expr,
@@ -1029,29 +1029,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncReadStream, typename DynamicBuffer_v1,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_until(AsyncReadStream& s,
-    DynamicBuffer_v1&& buffers, char delim, ReadToken&& token,
-    constraint_t<
-      is_dynamic_buffer_v1<decay_t<DynamicBuffer_v1>>::value
-    >,
-    constraint_t<
-      !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
-    >)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_until_delim_v1<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v1&&>(buffers), delim))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_until_delim_v1<AsyncReadStream>(s),
-      token, static_cast<DynamicBuffer_v1&&>(buffers), delim);
-}
-
 namespace detail
 {
   template <typename AsyncReadStream,
@@ -1280,32 +1257,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncReadStream, typename DynamicBuffer_v1,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_until(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
-    BOOST_ASIO_STRING_VIEW_PARAM delim, ReadToken&& token,
-    constraint_t<
-      is_dynamic_buffer_v1<decay_t<DynamicBuffer_v1>>::value
-    >,
-    constraint_t<
-      !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
-    >)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_until_delim_string_v1<
-          AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v1&&>(buffers),
-        static_cast<std::string>(delim)))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_until_delim_string_v1<AsyncReadStream>(s),
-      token, static_cast<DynamicBuffer_v1&&>(buffers),
-      static_cast<std::string>(delim));
-}
-
 #if !defined(BOOST_ASIO_NO_EXTENSIONS)
 #if defined(BOOST_ASIO_HAS_BOOST_REGEX)
 
@@ -1538,29 +1489,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncReadStream, typename DynamicBuffer_v1, typename Traits,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_until(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
-    const boost::basic_regex<char, Traits>& expr, ReadToken&& token,
-    constraint_t<
-      is_dynamic_buffer_v1<decay_t<DynamicBuffer_v1>>::value
-    >,
-    constraint_t<
-      !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
-    >)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_until_expr_v1<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v1&&>(buffers), expr))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_until_expr_v1<AsyncReadStream>(s),
-      token, static_cast<DynamicBuffer_v1&&>(buffers), expr);
-}
-
 #endif // defined(BOOST_ASIO_HAS_BOOST_REGEX)
 
 namespace detail
@@ -1791,117 +1719,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncReadStream,
-    typename DynamicBuffer_v1, typename MatchCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_until(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
-    MatchCondition match_condition, ReadToken&& token,
-    constraint_t<
-      is_match_condition<MatchCondition>::value
-    >,
-    constraint_t<
-      is_dynamic_buffer_v1<decay_t<DynamicBuffer_v1>>::value
-    >,
-    constraint_t<
-      !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
-    >)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_until_match_v1<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v1&&>(buffers),
-        match_condition))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_until_match_v1<AsyncReadStream>(s),
-      token, static_cast<DynamicBuffer_v1&&>(buffers),
-      match_condition);
-}
-
-#if !defined(BOOST_ASIO_NO_IOSTREAM)
-
-template <typename AsyncReadStream, typename Allocator,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_until(AsyncReadStream& s,
-    boost::asio::basic_streambuf<Allocator>& b, char delim, ReadToken&& token)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_until_delim_v1<AsyncReadStream>>(),
-        token, basic_streambuf_ref<Allocator>(b), delim))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_until_delim_v1<AsyncReadStream>(s),
-      token, basic_streambuf_ref<Allocator>(b), delim);
-}
-
-template <typename AsyncReadStream, typename Allocator,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_until(AsyncReadStream& s,
-    boost::asio::basic_streambuf<Allocator>& b,
-    BOOST_ASIO_STRING_VIEW_PARAM delim, ReadToken&& token)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_until_delim_string_v1<
-          AsyncReadStream>>(),
-        token, basic_streambuf_ref<Allocator>(b),
-        static_cast<std::string>(delim)))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_until_delim_string_v1<AsyncReadStream>(s),
-      token, basic_streambuf_ref<Allocator>(b),
-      static_cast<std::string>(delim));
-}
-
-#if defined(BOOST_ASIO_HAS_BOOST_REGEX)
-
-template <typename AsyncReadStream, typename Allocator, typename Traits,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_until(AsyncReadStream& s,
-    boost::asio::basic_streambuf<Allocator>& b,
-    const boost::basic_regex<char, Traits>& expr, ReadToken&& token)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_until_expr_v1<AsyncReadStream>>(),
-        token, basic_streambuf_ref<Allocator>(b), expr))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_until_expr_v1<AsyncReadStream>(s),
-      token, basic_streambuf_ref<Allocator>(b), expr);
-}
-
-#endif // defined(BOOST_ASIO_HAS_BOOST_REGEX)
-
-template <typename AsyncReadStream, typename Allocator, typename MatchCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_until(AsyncReadStream& s,
-    boost::asio::basic_streambuf<Allocator>& b,
-    MatchCondition match_condition, ReadToken&& token,
-    constraint_t<is_match_condition<MatchCondition>::value>)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_until_match_v1<AsyncReadStream>>(),
-        token, basic_streambuf_ref<Allocator>(b), match_condition))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_until_match_v1<AsyncReadStream>(s),
-      token, basic_streambuf_ref<Allocator>(b), match_condition);
-}
-
-#endif // !defined(BOOST_ASIO_NO_IOSTREAM)
 #endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
 #endif // !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1)
 
@@ -2129,26 +1946,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncReadStream, typename DynamicBuffer_v2,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_until(AsyncReadStream& s,
-    DynamicBuffer_v2 buffers, char delim, ReadToken&& token,
-    constraint_t<
-      is_dynamic_buffer_v2<DynamicBuffer_v2>::value
-    >)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_until_delim_v2<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v2&&>(buffers), delim))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_until_delim_v2<AsyncReadStream>(s),
-      token, static_cast<DynamicBuffer_v2&&>(buffers), delim);
-}
-
 namespace detail
 {
   template <typename AsyncReadStream,
@@ -2385,30 +2182,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncReadStream,
-    typename DynamicBuffer_v2,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_until(AsyncReadStream& s, DynamicBuffer_v2 buffers,
-    BOOST_ASIO_STRING_VIEW_PARAM delim, ReadToken&& token,
-    constraint_t<
-      is_dynamic_buffer_v2<DynamicBuffer_v2>::value
-    >)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_until_delim_string_v2<
-          AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v2&&>(buffers),
-        static_cast<std::string>(delim)))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_until_delim_string_v2<AsyncReadStream>(s),
-      token, static_cast<DynamicBuffer_v2&&>(buffers),
-      static_cast<std::string>(delim));
-}
-
 #if !defined(BOOST_ASIO_NO_EXTENSIONS)
 #if defined(BOOST_ASIO_HAS_BOOST_REGEX)
 
@@ -2650,26 +2423,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncReadStream, typename DynamicBuffer_v2, typename Traits,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_until(AsyncReadStream& s, DynamicBuffer_v2 buffers,
-    const boost::basic_regex<char, Traits>& expr, ReadToken&& token,
-    constraint_t<
-      is_dynamic_buffer_v2<DynamicBuffer_v2>::value
-    >)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_until_expr_v2<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v2&&>(buffers), expr))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_until_expr_v2<AsyncReadStream>(s),
-      token, static_cast<DynamicBuffer_v2&&>(buffers), expr);
-}
-
 #endif // defined(BOOST_ASIO_HAS_BOOST_REGEX)
 
 namespace detail
@@ -2907,32 +2660,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncReadStream,
-    typename DynamicBuffer_v2, typename MatchCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) ReadToken>
-inline auto async_read_until(AsyncReadStream& s, DynamicBuffer_v2 buffers,
-    MatchCondition match_condition, ReadToken&& token,
-    constraint_t<
-      is_match_condition<MatchCondition>::value
-    >,
-    constraint_t<
-      is_dynamic_buffer_v2<DynamicBuffer_v2>::value
-    >)
-  -> decltype(
-    async_initiate<ReadToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_read_until_match_v2<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v2&&>(buffers),
-        match_condition))
-{
-  return async_initiate<ReadToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_read_until_match_v2<AsyncReadStream>(s),
-      token, static_cast<DynamicBuffer_v2&&>(buffers),
-      match_condition);
-}
-
 #endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
 
 } // namespace asio
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/redirect_error.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/redirect_error.hpp
index f97a96b14e..b2f8ac7f39 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/impl/redirect_error.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/redirect_error.hpp
@@ -16,9 +16,11 @@
 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
 
 #include <boost/asio/detail/config.hpp>
+#include <boost/asio/associated_executor.hpp>
 #include <boost/asio/associator.hpp>
 #include <boost/asio/async_result.hpp>
 #include <boost/asio/detail/handler_cont_helpers.hpp>
+#include <boost/asio/detail/initiation_base.hpp>
 #include <boost/asio/detail/type_traits.hpp>
 #include <boost/system/system_error.hpp>
 
@@ -183,42 +185,52 @@ struct async_result<redirect_error_t<CompletionToken>, Signature>
   : async_result<CompletionToken,
       typename detail::redirect_error_signature<Signature>::type>
 {
-
-  struct init_wrapper
+  template <typename Initiation>
+  struct init_wrapper : detail::initiation_base<Initiation>
   {
-    explicit init_wrapper(boost::system::error_code& ec)
-      : ec_(ec)
+    using detail::initiation_base<Initiation>::initiation_base;
+
+    template <typename Handler, typename... Args>
+    void operator()(Handler&& handler,
+        boost::system::error_code* ec, Args&&... args) &&
     {
+      static_cast<Initiation&&>(*this)(
+          detail::redirect_error_handler<decay_t<Handler>>(
+            *ec, static_cast<Handler&&>(handler)),
+          static_cast<Args&&>(args)...);
     }
 
-    template <typename Handler, typename Initiation, typename... Args>
+    template <typename Handler, typename... Args>
     void operator()(Handler&& handler,
-        Initiation&& initiation, Args&&... args) const
+        boost::system::error_code* ec, Args&&... args) const &
     {
-      static_cast<Initiation&&>(initiation)(
+      static_cast<const Initiation&>(*this)(
           detail::redirect_error_handler<decay_t<Handler>>(
-            ec_, static_cast<Handler&&>(handler)),
+            *ec, static_cast<Handler&&>(handler)),
           static_cast<Args&&>(args)...);
     }
-
-    boost::system::error_code& ec_;
   };
 
   template <typename Initiation, typename RawCompletionToken, typename... Args>
   static auto initiate(Initiation&& initiation,
       RawCompletionToken&& token, Args&&... args)
     -> decltype(
-      async_initiate<CompletionToken,
+      async_initiate<
+        conditional_t<
+          is_const<remove_reference_t<RawCompletionToken>>::value,
+            const CompletionToken, CompletionToken>,
         typename detail::redirect_error_signature<Signature>::type>(
-          declval<init_wrapper>(), token.token_,
-          static_cast<Initiation&&>(initiation),
-          static_cast<Args&&>(args)...))
+          declval<init_wrapper<decay_t<Initiation>>>(),
+          token.token_, &token.ec_, static_cast<Args&&>(args)...))
   {
-    return async_initiate<CompletionToken,
+    return async_initiate<
+      conditional_t<
+        is_const<remove_reference_t<RawCompletionToken>>::value,
+          const CompletionToken, CompletionToken>,
       typename detail::redirect_error_signature<Signature>::type>(
-        init_wrapper(token.ec_), token.token_,
-        static_cast<Initiation&&>(initiation),
-        static_cast<Args&&>(args)...);
+        init_wrapper<decay_t<Initiation>>(
+          static_cast<Initiation&&>(initiation)),
+        token.token_, &token.ec_, static_cast<Args&&>(args)...);
   }
 };
 
@@ -242,6 +254,31 @@ struct associator<Associator,
   }
 };
 
+template <typename... Signatures>
+struct async_result<partial_redirect_error, Signatures...>
+{
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static auto initiate(Initiation&& initiation,
+      RawCompletionToken&& token, Args&&... args)
+    -> decltype(
+      async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        redirect_error_t<
+          default_completion_token_t<associated_executor_t<Initiation>>>(
+            default_completion_token_t<associated_executor_t<Initiation>>{},
+            token.ec_),
+        static_cast<Args&&>(args)...))
+  {
+    return async_initiate<Signatures...>(
+        static_cast<Initiation&&>(initiation),
+        redirect_error_t<
+          default_completion_token_t<associated_executor_t<Initiation>>>(
+            default_completion_token_t<associated_executor_t<Initiation>>{},
+            token.ec_),
+        static_cast<Args&&>(args)...);
+  }
+};
+
 #endif // !defined(GENERATING_DOCUMENTATION)
 
 } // namespace asio
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/spawn.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/spawn.hpp
index 04b6710ae4..03800c5ca5 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/impl/spawn.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/spawn.hpp
@@ -29,6 +29,7 @@
 #include <boost/asio/detail/noncopyable.hpp>
 #include <boost/asio/detail/type_traits.hpp>
 #include <boost/asio/detail/utility.hpp>
+#include <boost/asio/error.hpp>
 #include <boost/system/system_error.hpp>
 
 #if defined(BOOST_ASIO_HAS_BOOST_CONTEXT_FIBER)
@@ -976,7 +977,6 @@ class spawn_cancellation_handler
   Executor ex_;
 };
 
-
 template <typename Handler, typename Executor>
 class spawn_cancellation_handler<Handler, Executor,
     enable_if_t<
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/write.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/write.hpp
index e859f38c88..ff26e1773f 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/impl/write.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/write.hpp
@@ -63,6 +63,9 @@ inline std::size_t write(SyncWriteStream& s, const ConstBufferSequence& buffers,
     CompletionCondition completion_condition, boost::system::error_code& ec,
     constraint_t<
       is_const_buffer_sequence<ConstBufferSequence>::value
+    >,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     >)
 {
   return detail::write(s, buffers,
@@ -98,6 +101,9 @@ inline std::size_t write(SyncWriteStream& s, const ConstBufferSequence& buffers,
     CompletionCondition completion_condition,
     constraint_t<
       is_const_buffer_sequence<ConstBufferSequence>::value
+    >,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     >)
 {
   boost::system::error_code ec;
@@ -119,6 +125,9 @@ std::size_t write(SyncWriteStream& s,
     >,
     constraint_t<
       !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
+    >,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     >)
 {
   decay_t<DynamicBuffer_v1> b(
@@ -173,6 +182,9 @@ inline std::size_t write(SyncWriteStream& s,
     >,
     constraint_t<
       !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
+    >,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     >)
 {
   boost::system::error_code ec;
@@ -190,7 +202,10 @@ template <typename SyncWriteStream, typename Allocator,
     typename CompletionCondition>
 inline std::size_t write(SyncWriteStream& s,
     boost::asio::basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition, boost::system::error_code& ec)
+    CompletionCondition completion_condition, boost::system::error_code& ec,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    >)
 {
   return write(s, basic_streambuf_ref<Allocator>(b),
       static_cast<CompletionCondition&&>(completion_condition), ec);
@@ -215,7 +230,10 @@ template <typename SyncWriteStream, typename Allocator,
     typename CompletionCondition>
 inline std::size_t write(SyncWriteStream& s,
     boost::asio::basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition)
+    CompletionCondition completion_condition,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    >)
 {
   return write(s, basic_streambuf_ref<Allocator>(b),
       static_cast<CompletionCondition&&>(completion_condition));
@@ -231,6 +249,9 @@ std::size_t write(SyncWriteStream& s, DynamicBuffer_v2 buffers,
     CompletionCondition completion_condition, boost::system::error_code& ec,
     constraint_t<
       is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+    >,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     >)
 {
   std::size_t bytes_transferred = write(s, buffers.data(0, buffers.size()),
@@ -270,6 +291,9 @@ inline std::size_t write(SyncWriteStream& s, DynamicBuffer_v2 buffers,
     CompletionCondition completion_condition,
     constraint_t<
       is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+    >,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     >)
 {
   boost::system::error_code ec;
@@ -463,49 +487,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncWriteStream,
-    typename ConstBufferSequence, typename CompletionCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-inline auto async_write(AsyncWriteStream& s, const ConstBufferSequence& buffers,
-    CompletionCondition completion_condition, WriteToken&& token,
-    constraint_t<
-      is_const_buffer_sequence<ConstBufferSequence>::value
-    >)
-  -> decltype(
-    async_initiate<WriteToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_write<AsyncWriteStream>>(),
-        token, buffers,
-        static_cast<CompletionCondition&&>(completion_condition)))
-{
-  return async_initiate<WriteToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_write<AsyncWriteStream>(s),
-      token, buffers,
-      static_cast<CompletionCondition&&>(completion_condition));
-}
-
-template <typename AsyncWriteStream, typename ConstBufferSequence,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-inline auto async_write(AsyncWriteStream& s,
-    const ConstBufferSequence& buffers, WriteToken&& token,
-    constraint_t<
-      is_const_buffer_sequence<ConstBufferSequence>::value
-    >)
-  -> decltype(
-    async_initiate<WriteToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_write<AsyncWriteStream>>(),
-        token, buffers, transfer_all()))
-{
-  return async_initiate<WriteToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_write<AsyncWriteStream>(s),
-      token, buffers, transfer_all());
-}
-
 #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1)
 
 namespace detail
@@ -650,101 +631,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncWriteStream, typename DynamicBuffer_v1,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-inline auto async_write(AsyncWriteStream& s,
-    DynamicBuffer_v1&& buffers, WriteToken&& token,
-    constraint_t<
-      is_dynamic_buffer_v1<decay_t<DynamicBuffer_v1>>::value
-    >,
-    constraint_t<
-      !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
-    >)
-  -> decltype(
-    async_initiate<WriteToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>>(),
-        token, static_cast<DynamicBuffer_v1&&>(buffers),
-        transfer_all()))
-{
-  return async_initiate<WriteToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>(s),
-      token, static_cast<DynamicBuffer_v1&&>(buffers),
-      transfer_all());
-}
-
-template <typename AsyncWriteStream,
-    typename DynamicBuffer_v1, typename CompletionCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-inline auto async_write(AsyncWriteStream& s, DynamicBuffer_v1&& buffers,
-    CompletionCondition completion_condition, WriteToken&& token,
-    constraint_t<
-      is_dynamic_buffer_v1<decay_t<DynamicBuffer_v1>>::value
-    >,
-    constraint_t<
-      !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
-    >)
-  -> decltype(
-    async_initiate<WriteToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>>(),
-        token, static_cast<DynamicBuffer_v1&&>(buffers),
-        static_cast<CompletionCondition&&>(completion_condition)))
-{
-  return async_initiate<WriteToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>(s),
-      token, static_cast<DynamicBuffer_v1&&>(buffers),
-      static_cast<CompletionCondition&&>(completion_condition));
-}
-
-#if !defined(BOOST_ASIO_NO_EXTENSIONS)
-#if !defined(BOOST_ASIO_NO_IOSTREAM)
-
-template <typename AsyncWriteStream, typename Allocator,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-inline auto async_write(AsyncWriteStream& s,
-    boost::asio::basic_streambuf<Allocator>& b,
-    WriteToken&& token)
-  -> decltype(
-    async_initiate<WriteToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>>(),
-        token, basic_streambuf_ref<Allocator>(b), transfer_all()))
-{
-  return async_initiate<WriteToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>(s),
-      token, basic_streambuf_ref<Allocator>(b), transfer_all());
-}
-
-template <typename AsyncWriteStream,
-    typename Allocator, typename CompletionCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-inline auto async_write(AsyncWriteStream& s,
-    boost::asio::basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition, WriteToken&& token)
-  -> decltype(
-    async_initiate<WriteToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>>(),
-        token, basic_streambuf_ref<Allocator>(b),
-        static_cast<CompletionCondition&&>(completion_condition)))
-{
-  return async_initiate<WriteToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>(s),
-      token, basic_streambuf_ref<Allocator>(b),
-      static_cast<CompletionCondition&&>(completion_condition));
-}
-
-#endif // !defined(BOOST_ASIO_NO_IOSTREAM)
-#endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
 #endif // !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1)
 
 namespace detail
@@ -888,51 +774,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncWriteStream, typename DynamicBuffer_v2,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-inline auto async_write(AsyncWriteStream& s,
-    DynamicBuffer_v2 buffers, WriteToken&& token,
-    constraint_t<
-      is_dynamic_buffer_v2<DynamicBuffer_v2>::value
-    >)
-  -> decltype(
-    async_initiate<WriteToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_write_dynbuf_v2<AsyncWriteStream>>(),
-        token, static_cast<DynamicBuffer_v2&&>(buffers),
-        transfer_all()))
-{
-  return async_initiate<WriteToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_write_dynbuf_v2<AsyncWriteStream>(s),
-      token, static_cast<DynamicBuffer_v2&&>(buffers),
-      transfer_all());
-}
-
-template <typename AsyncWriteStream,
-    typename DynamicBuffer_v2, typename CompletionCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-inline auto async_write(AsyncWriteStream& s, DynamicBuffer_v2 buffers,
-    CompletionCondition completion_condition, WriteToken&& token,
-    constraint_t<
-      is_dynamic_buffer_v2<DynamicBuffer_v2>::value
-    >)
-  -> decltype(
-    async_initiate<WriteToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_write_dynbuf_v2<AsyncWriteStream>>(),
-        token, static_cast<DynamicBuffer_v2&&>(buffers),
-        static_cast<CompletionCondition&&>(completion_condition)))
-{
-  return async_initiate<WriteToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_write_dynbuf_v2<AsyncWriteStream>(s),
-      token, static_cast<DynamicBuffer_v2&&>(buffers),
-      static_cast<CompletionCondition&&>(completion_condition));
-}
-
 } // namespace asio
 } // namespace boost
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/impl/write_at.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/impl/write_at.hpp
index f516b88a65..faa0ed2cc9 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/impl/write_at.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/impl/write_at.hpp
@@ -65,7 +65,10 @@ template <typename SyncRandomAccessWriteDevice, typename ConstBufferSequence,
     typename CompletionCondition>
 std::size_t write_at(SyncRandomAccessWriteDevice& d,
     uint64_t offset, const ConstBufferSequence& buffers,
-    CompletionCondition completion_condition, boost::system::error_code& ec)
+    CompletionCondition completion_condition, boost::system::error_code& ec,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    >)
 {
   return detail::write_at_buffer_sequence(d, offset, buffers,
       boost::asio::buffer_sequence_begin(buffers),
@@ -95,7 +98,10 @@ template <typename SyncRandomAccessWriteDevice, typename ConstBufferSequence,
     typename CompletionCondition>
 inline std::size_t write_at(SyncRandomAccessWriteDevice& d,
     uint64_t offset, const ConstBufferSequence& buffers,
-    CompletionCondition completion_condition)
+    CompletionCondition completion_condition,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    >)
 {
   boost::system::error_code ec;
   std::size_t bytes_transferred = write_at(d, offset, buffers,
@@ -111,7 +117,10 @@ template <typename SyncRandomAccessWriteDevice, typename Allocator,
     typename CompletionCondition>
 std::size_t write_at(SyncRandomAccessWriteDevice& d,
     uint64_t offset, boost::asio::basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition, boost::system::error_code& ec)
+    CompletionCondition completion_condition, boost::system::error_code& ec,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    >)
 {
   std::size_t bytes_transferred = write_at(d, offset, b.data(),
       static_cast<CompletionCondition&&>(completion_condition), ec);
@@ -141,7 +150,10 @@ template <typename SyncRandomAccessWriteDevice, typename Allocator,
     typename CompletionCondition>
 inline std::size_t write_at(SyncRandomAccessWriteDevice& d,
     uint64_t offset, boost::asio::basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition)
+    CompletionCondition completion_condition,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    >)
 {
   boost::system::error_code ec;
   std::size_t bytes_transferred = write_at(d, offset, b,
@@ -345,46 +357,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncRandomAccessWriteDevice,
-    typename ConstBufferSequence, typename CompletionCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-inline auto async_write_at(AsyncRandomAccessWriteDevice& d,
-    uint64_t offset, const ConstBufferSequence& buffers,
-    CompletionCondition completion_condition, WriteToken&& token)
-  -> decltype(
-    async_initiate<WriteToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_write_at<
-          AsyncRandomAccessWriteDevice>>(),
-        token, offset, buffers,
-        static_cast<CompletionCondition&&>(completion_condition)))
-{
-  return async_initiate<WriteToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_write_at<AsyncRandomAccessWriteDevice>(d),
-      token, offset, buffers,
-      static_cast<CompletionCondition&&>(completion_condition));
-}
-
-template <typename AsyncRandomAccessWriteDevice, typename ConstBufferSequence,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-inline auto async_write_at(AsyncRandomAccessWriteDevice& d,
-    uint64_t offset, const ConstBufferSequence& buffers, WriteToken&& token)
-  -> decltype(
-    async_initiate<WriteToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_write_at<
-          AsyncRandomAccessWriteDevice>>(),
-        token, offset, buffers, transfer_all()))
-{
-  return async_initiate<WriteToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_write_at<AsyncRandomAccessWriteDevice>(d),
-      token, offset, buffers, transfer_all());
-}
-
 #if !defined(BOOST_ASIO_NO_EXTENSIONS)
 #if !defined(BOOST_ASIO_NO_IOSTREAM)
 
@@ -499,49 +471,6 @@ struct associator<Associator,
 
 #endif // !defined(GENERATING_DOCUMENTATION)
 
-template <typename AsyncRandomAccessWriteDevice,
-    typename Allocator, typename CompletionCondition,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-inline auto async_write_at(AsyncRandomAccessWriteDevice& d,
-    uint64_t offset, boost::asio::basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition, WriteToken&& token)
-  -> decltype(
-    async_initiate<WriteToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_write_at_streambuf<
-          AsyncRandomAccessWriteDevice>>(),
-        token, offset, &b,
-        static_cast<CompletionCondition&&>(completion_condition)))
-{
-  return async_initiate<WriteToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_write_at_streambuf<
-        AsyncRandomAccessWriteDevice>(d),
-      token, offset, &b,
-      static_cast<CompletionCondition&&>(completion_condition));
-}
-
-template <typename AsyncRandomAccessWriteDevice, typename Allocator,
-    BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-inline auto async_write_at(AsyncRandomAccessWriteDevice& d,
-    uint64_t offset, boost::asio::basic_streambuf<Allocator>& b,
-    WriteToken&& token)
-  -> decltype(
-    async_initiate<WriteToken,
-      void (boost::system::error_code, std::size_t)>(
-        declval<detail::initiate_async_write_at_streambuf<
-          AsyncRandomAccessWriteDevice>>(),
-        token, offset, &b, transfer_all()))
-{
-  return async_initiate<WriteToken,
-    void (boost::system::error_code, std::size_t)>(
-      detail::initiate_async_write_at_streambuf<
-        AsyncRandomAccessWriteDevice>(d),
-      token, offset, &b, transfer_all());
-}
-
 #endif // !defined(BOOST_ASIO_NO_IOSTREAM)
 #endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/io_context_strand.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/io_context_strand.hpp
index e2864763a1..c612584e52 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/io_context_strand.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/io_context_strand.hpp
@@ -55,18 +55,18 @@ namespace asio {
  * if any of the following conditions are true:
  *
  * @li @c s.post(a) happens-before @c s.post(b)
- * 
+ *
  * @li @c s.post(a) happens-before @c s.dispatch(b), where the latter is
  * performed outside the strand
- * 
+ *
  * @li @c s.dispatch(a) happens-before @c s.post(b), where the former is
  * performed outside the strand
- * 
+ *
  * @li @c s.dispatch(a) happens-before @c s.dispatch(b), where both are
  * performed outside the strand
- *   
+ *
  * then @c a() happens-before @c b()
- * 
+ *
  * Note that in the following case:
  * @code async_op_1(..., s.wrap(a));
  * async_op_2(..., s.wrap(b)); @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/ip/basic_resolver.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/ip/basic_resolver.hpp
index e46a8333dd..9ed8578005 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/ip/basic_resolver.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/ip/basic_resolver.hpp
@@ -663,7 +663,7 @@ class basic_resolver
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * A successful resolve operation is guaranteed to pass a non-empty range to
    * the handler.
@@ -715,7 +715,7 @@ class basic_resolver
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * A successful resolve operation is guaranteed to pass a non-empty range to
    * the handler.
@@ -784,7 +784,7 @@ class basic_resolver
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * A successful resolve operation is guaranteed to pass a non-empty range to
    * the handler.
@@ -855,7 +855,7 @@ class basic_resolver
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * A successful resolve operation is guaranteed to pass a non-empty range to
    * the handler.
@@ -927,7 +927,7 @@ class basic_resolver
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * A successful resolve operation is guaranteed to pass a non-empty range to
    * the handler.
@@ -1032,7 +1032,7 @@ class basic_resolver
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * A successful resolve operation is guaranteed to pass a non-empty range to
    * the handler.
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/ip/detail/socket_option.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/ip/detail/socket_option.hpp
index a806d344fd..3ae928c7f6 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/ip/detail/socket_option.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/ip/detail/socket_option.hpp
@@ -40,7 +40,7 @@ class multicast_enable_loopback
 #if defined(__sun) || defined(__osf__)
   typedef unsigned char ipv4_value_type;
   typedef unsigned char ipv6_value_type;
-#elif defined(_AIX) || defined(__hpux) || defined(__QNXNTO__) 
+#elif defined(_AIX) || defined(__hpux) || defined(__QNXNTO__)
   typedef unsigned char ipv4_value_type;
   typedef unsigned int ipv6_value_type;
 #else
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/ip/impl/address_v6.ipp b/src/cxx_supportlib/vendor-modified/boost/asio/ip/impl/address_v6.ipp
index cf81cca410..adb7ae1d4e 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/ip/impl/address_v6.ipp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/ip/impl/address_v6.ipp
@@ -282,7 +282,7 @@ address_v6 make_address_v6(const char* str,
   if (boost::asio::detail::socket_ops::inet_pton(
         BOOST_ASIO_OS_DEF(AF_INET6), str, &bytes[0], &scope_id, ec) <= 0)
     return address_v6();
-  return address_v6(bytes, scope_id);
+  return address_v6(bytes, static_cast<scope_id_type>(scope_id));
 }
 
 address_v6 make_address_v6(const std::string& str)
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/placeholders.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/placeholders.hpp
index eacc28c727..5476c800ce 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/placeholders.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/placeholders.hpp
@@ -59,12 +59,18 @@ unspecified signal_number;
 
 #else
 
-static constexpr auto& error = std::placeholders::_1;
-static constexpr auto& bytes_transferred = std::placeholders::_2;
-static constexpr auto& iterator = std::placeholders::_2;
-static constexpr auto& results = std::placeholders::_2;
-static constexpr auto& endpoint = std::placeholders::_2;
-static constexpr auto& signal_number = std::placeholders::_2;
+static BOOST_ASIO_INLINE_VARIABLE constexpr auto& error
+  = std::placeholders::_1;
+static BOOST_ASIO_INLINE_VARIABLE constexpr auto& bytes_transferred
+  = std::placeholders::_2;
+static BOOST_ASIO_INLINE_VARIABLE constexpr auto& iterator
+  = std::placeholders::_2;
+static BOOST_ASIO_INLINE_VARIABLE constexpr auto& results
+  = std::placeholders::_2;
+static BOOST_ASIO_INLINE_VARIABLE constexpr auto& endpoint
+  = std::placeholders::_2;
+static BOOST_ASIO_INLINE_VARIABLE constexpr auto& signal_number
+  = std::placeholders::_2;
 
 #endif
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/posix/basic_descriptor.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/posix/basic_descriptor.hpp
index 8e22760ec4..82ea554dfc 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/posix/basic_descriptor.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/posix/basic_descriptor.hpp
@@ -661,7 +661,7 @@ class basic_descriptor
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code) @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/posix/basic_stream_descriptor.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/posix/basic_stream_descriptor.hpp
index 882f27c71d..149e85db39 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/posix/basic_stream_descriptor.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/posix/basic_stream_descriptor.hpp
@@ -308,7 +308,7 @@ class basic_stream_descriptor
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -437,7 +437,7 @@ class basic_stream_descriptor
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/read.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/read.hpp
index b66c79e17e..6e1733d60c 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/read.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/read.hpp
@@ -185,6 +185,9 @@ std::size_t read(SyncReadStream& s, const MutableBufferSequence& buffers,
     CompletionCondition completion_condition,
     constraint_t<
       is_mutable_buffer_sequence<MutableBufferSequence>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0);
 
 /// Attempt to read a certain amount of data from a stream before returning.
@@ -232,6 +235,9 @@ std::size_t read(SyncReadStream& s, const MutableBufferSequence& buffers,
     CompletionCondition completion_condition, boost::system::error_code& ec,
     constraint_t<
       is_mutable_buffer_sequence<MutableBufferSequence>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0);
 
 #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1)
@@ -356,6 +362,9 @@ std::size_t read(SyncReadStream& s,
     > = 0,
     constraint_t<
       !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0);
 
 /// Attempt to read a certain amount of data from a stream before returning.
@@ -405,6 +414,9 @@ std::size_t read(SyncReadStream& s,
     > = 0,
     constraint_t<
       !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0);
 
 #if !defined(BOOST_ASIO_NO_EXTENSIONS)
@@ -507,7 +519,10 @@ std::size_t read(SyncReadStream& s, basic_streambuf<Allocator>& b,
 template <typename SyncReadStream, typename Allocator,
     typename CompletionCondition>
 std::size_t read(SyncReadStream& s, basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition);
+    CompletionCondition completion_condition,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0);
 
 /// Attempt to read a certain amount of data from a stream before returning.
 /**
@@ -548,7 +563,10 @@ std::size_t read(SyncReadStream& s, basic_streambuf<Allocator>& b,
 template <typename SyncReadStream, typename Allocator,
     typename CompletionCondition>
 std::size_t read(SyncReadStream& s, basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition, boost::system::error_code& ec);
+    CompletionCondition completion_condition, boost::system::error_code& ec,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0);
 
 #endif // !defined(BOOST_ASIO_NO_IOSTREAM)
 #endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
@@ -662,6 +680,9 @@ std::size_t read(SyncReadStream& s, DynamicBuffer_v2 buffers,
     CompletionCondition completion_condition,
     constraint_t<
       is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0);
 
 /// Attempt to read a certain amount of data from a stream before returning.
@@ -707,6 +728,9 @@ std::size_t read(SyncReadStream& s, DynamicBuffer_v2 buffers,
     CompletionCondition completion_condition, boost::system::error_code& ec,
     constraint_t<
       is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0);
 
 /*@}*/
@@ -763,7 +787,7 @@ std::size_t read(SyncReadStream& s, DynamicBuffer_v2 buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -798,17 +822,26 @@ template <typename AsyncReadStream, typename MutableBufferSequence,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read(AsyncReadStream& s, const MutableBufferSequence& buffers,
+inline auto async_read(AsyncReadStream& s, const MutableBufferSequence& buffers,
     ReadToken&& token = default_completion_token_t<
       typename AsyncReadStream::executor_type>(),
     constraint_t<
       is_mutable_buffer_sequence<MutableBufferSequence>::value
+    > = 0,
+    constraint_t<
+      !is_completion_condition<ReadToken>::value
     > = 0)
   -> decltype(
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read<AsyncReadStream>>(),
-        token, buffers, transfer_all()));
+        token, buffers, transfer_all()))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read<AsyncReadStream>(s),
+      token, buffers, transfer_all());
+}
 
 /// Start an asynchronous operation to read a certain amount of data from a
 /// stream.
@@ -863,7 +896,7 @@ auto async_read(AsyncReadStream& s, const MutableBufferSequence& buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -894,19 +927,28 @@ template <typename AsyncReadStream,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read(AsyncReadStream& s, const MutableBufferSequence& buffers,
+inline auto async_read(AsyncReadStream& s, const MutableBufferSequence& buffers,
     CompletionCondition completion_condition,
     ReadToken&& token = default_completion_token_t<
       typename AsyncReadStream::executor_type>(),
     constraint_t<
       is_mutable_buffer_sequence<MutableBufferSequence>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0)
   -> decltype(
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read<AsyncReadStream>>(),
         token, buffers,
-        static_cast<CompletionCondition&&>(completion_condition)));
+        static_cast<CompletionCondition&&>(completion_condition)))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read<AsyncReadStream>(s), token, buffers,
+      static_cast<CompletionCondition&&>(completion_condition));
+}
 
 #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1)
 
@@ -954,7 +996,7 @@ auto async_read(AsyncReadStream& s, const MutableBufferSequence& buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -980,7 +1022,7 @@ template <typename AsyncReadStream, typename DynamicBuffer_v1,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
+inline auto async_read(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
     ReadToken&& token = default_completion_token_t<
       typename AsyncReadStream::executor_type>(),
     constraint_t<
@@ -988,12 +1030,21 @@ auto async_read(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
     > = 0,
     constraint_t<
       !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
+    > = 0,
+    constraint_t<
+      !is_completion_condition<ReadToken>::value
     > = 0)
   -> decltype(
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_dynbuf_v1<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v1&&>(buffers), transfer_all()));
+        token, static_cast<DynamicBuffer_v1&&>(buffers), transfer_all()))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_dynbuf_v1<AsyncReadStream>(s),
+      token, static_cast<DynamicBuffer_v1&&>(buffers), transfer_all());
+}
 
 /// Start an asynchronous operation to read a certain amount of data from a
 /// stream.
@@ -1053,7 +1104,7 @@ auto async_read(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1074,7 +1125,7 @@ template <typename AsyncReadStream,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
+inline auto async_read(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
     CompletionCondition completion_condition,
     ReadToken&& token = default_completion_token_t<
       typename AsyncReadStream::executor_type>(),
@@ -1083,13 +1134,23 @@ auto async_read(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
     > = 0,
     constraint_t<
       !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0)
   -> decltype(
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_dynbuf_v1<AsyncReadStream>>(),
         token, static_cast<DynamicBuffer_v1&&>(buffers),
-        static_cast<CompletionCondition&&>(completion_condition)));
+        static_cast<CompletionCondition&&>(completion_condition)))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_dynbuf_v1<AsyncReadStream>(s),
+      token, static_cast<DynamicBuffer_v1&&>(buffers),
+      static_cast<CompletionCondition&&>(completion_condition));
+}
 
 #if !defined(BOOST_ASIO_NO_EXTENSIONS)
 #if !defined(BOOST_ASIO_NO_IOSTREAM)
@@ -1136,7 +1197,7 @@ auto async_read(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1162,14 +1223,23 @@ template <typename AsyncReadStream, typename Allocator,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read(AsyncReadStream& s, basic_streambuf<Allocator>& b,
+inline auto async_read(AsyncReadStream& s, basic_streambuf<Allocator>& b,
     ReadToken&& token = default_completion_token_t<
-      typename AsyncReadStream::executor_type>())
+      typename AsyncReadStream::executor_type>(),
+    constraint_t<
+      !is_completion_condition<ReadToken>::value
+    > = 0)
   -> decltype(
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_dynbuf_v1<AsyncReadStream>>(),
-        token, basic_streambuf_ref<Allocator>(b), transfer_all()));
+        token, basic_streambuf_ref<Allocator>(b), transfer_all()))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_dynbuf_v1<AsyncReadStream>(s),
+      token, basic_streambuf_ref<Allocator>(b), transfer_all());
+}
 
 /// Start an asynchronous operation to read a certain amount of data from a
 /// stream.
@@ -1227,7 +1297,7 @@ auto async_read(AsyncReadStream& s, basic_streambuf<Allocator>& b,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1248,16 +1318,26 @@ template <typename AsyncReadStream,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read(AsyncReadStream& s, basic_streambuf<Allocator>& b,
+inline auto async_read(AsyncReadStream& s, basic_streambuf<Allocator>& b,
     CompletionCondition completion_condition,
     ReadToken&& token = default_completion_token_t<
-      typename AsyncReadStream::executor_type>())
+      typename AsyncReadStream::executor_type>(),
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0)
   -> decltype(
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_dynbuf_v1<AsyncReadStream>>(),
         token, basic_streambuf_ref<Allocator>(b),
-        static_cast<CompletionCondition&&>(completion_condition)));
+        static_cast<CompletionCondition&&>(completion_condition)))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_dynbuf_v1<AsyncReadStream>(s),
+      token, basic_streambuf_ref<Allocator>(b),
+      static_cast<CompletionCondition&&>(completion_condition));
+}
 
 #endif // !defined(BOOST_ASIO_NO_IOSTREAM)
 #endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
@@ -1307,7 +1387,7 @@ auto async_read(AsyncReadStream& s, basic_streambuf<Allocator>& b,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1333,17 +1413,26 @@ template <typename AsyncReadStream, typename DynamicBuffer_v2,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read(AsyncReadStream& s, DynamicBuffer_v2 buffers,
+inline auto async_read(AsyncReadStream& s, DynamicBuffer_v2 buffers,
     ReadToken&& token = default_completion_token_t<
       typename AsyncReadStream::executor_type>(),
     constraint_t<
       is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+    > = 0,
+    constraint_t<
+      !is_completion_condition<ReadToken>::value
     > = 0)
   -> decltype(
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_dynbuf_v2<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v2&&>(buffers), transfer_all()));
+        token, static_cast<DynamicBuffer_v2&&>(buffers), transfer_all()))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_dynbuf_v2<AsyncReadStream>(s),
+      token, static_cast<DynamicBuffer_v2&&>(buffers), transfer_all());
+}
 
 /// Start an asynchronous operation to read a certain amount of data from a
 /// stream.
@@ -1403,7 +1492,7 @@ auto async_read(AsyncReadStream& s, DynamicBuffer_v2 buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1424,19 +1513,29 @@ template <typename AsyncReadStream,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read(AsyncReadStream& s, DynamicBuffer_v2 buffers,
+inline auto async_read(AsyncReadStream& s, DynamicBuffer_v2 buffers,
     CompletionCondition completion_condition,
     ReadToken&& token = default_completion_token_t<
       typename AsyncReadStream::executor_type>(),
     constraint_t<
       is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0)
   -> decltype(
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_dynbuf_v2<AsyncReadStream>>(),
         token, static_cast<DynamicBuffer_v2&&>(buffers),
-        static_cast<CompletionCondition&&>(completion_condition)));
+        static_cast<CompletionCondition&&>(completion_condition)))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_dynbuf_v2<AsyncReadStream>(s),
+      token, static_cast<DynamicBuffer_v2&&>(buffers),
+      static_cast<CompletionCondition&&>(completion_condition));
+}
 
 /*@}*/
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/read_at.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/read_at.hpp
index 482d169bf4..ee6f267fcb 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/read_at.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/read_at.hpp
@@ -191,7 +191,10 @@ template <typename SyncRandomAccessReadDevice, typename MutableBufferSequence,
     typename CompletionCondition>
 std::size_t read_at(SyncRandomAccessReadDevice& d,
     uint64_t offset, const MutableBufferSequence& buffers,
-    CompletionCondition completion_condition);
+    CompletionCondition completion_condition,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0);
 
 /// Attempt to read a certain amount of data at the specified offset before
 /// returning.
@@ -240,7 +243,10 @@ template <typename SyncRandomAccessReadDevice, typename MutableBufferSequence,
     typename CompletionCondition>
 std::size_t read_at(SyncRandomAccessReadDevice& d,
     uint64_t offset, const MutableBufferSequence& buffers,
-    CompletionCondition completion_condition, boost::system::error_code& ec);
+    CompletionCondition completion_condition, boost::system::error_code& ec,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0);
 
 #if !defined(BOOST_ASIO_NO_EXTENSIONS)
 #if !defined(BOOST_ASIO_NO_IOSTREAM)
@@ -351,7 +357,10 @@ template <typename SyncRandomAccessReadDevice, typename Allocator,
     typename CompletionCondition>
 std::size_t read_at(SyncRandomAccessReadDevice& d,
     uint64_t offset, basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition);
+    CompletionCondition completion_condition,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0);
 
 /// Attempt to read a certain amount of data at the specified offset before
 /// returning.
@@ -395,7 +404,10 @@ template <typename SyncRandomAccessReadDevice, typename Allocator,
     typename CompletionCondition>
 std::size_t read_at(SyncRandomAccessReadDevice& d,
     uint64_t offset, basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition, boost::system::error_code& ec);
+    CompletionCondition completion_condition, boost::system::error_code& ec,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0);
 
 #endif // !defined(BOOST_ASIO_NO_IOSTREAM)
 #endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
@@ -454,7 +466,7 @@ std::size_t read_at(SyncRandomAccessReadDevice& d,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -489,15 +501,24 @@ template <typename AsyncRandomAccessReadDevice, typename MutableBufferSequence,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncRandomAccessReadDevice::executor_type>>
-auto async_read_at(AsyncRandomAccessReadDevice& d,
+inline auto async_read_at(AsyncRandomAccessReadDevice& d,
     uint64_t offset, const MutableBufferSequence& buffers,
     ReadToken&& token = default_completion_token_t<
-      typename AsyncRandomAccessReadDevice::executor_type>())
+      typename AsyncRandomAccessReadDevice::executor_type>(),
+    constraint_t<
+      !is_completion_condition<ReadToken>::value
+    > = 0)
   -> decltype(
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_at<AsyncRandomAccessReadDevice>>(),
-        token, offset, buffers, transfer_all()));
+        token, offset, buffers, transfer_all()))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_at<AsyncRandomAccessReadDevice>(d),
+      token, offset, buffers, transfer_all());
+}
 
 /// Start an asynchronous operation to read a certain amount of data at the
 /// specified offset.
@@ -555,7 +576,7 @@ auto async_read_at(AsyncRandomAccessReadDevice& d,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -586,17 +607,27 @@ template <typename AsyncRandomAccessReadDevice,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncRandomAccessReadDevice::executor_type>>
-auto async_read_at(AsyncRandomAccessReadDevice& d,
+inline auto async_read_at(AsyncRandomAccessReadDevice& d,
     uint64_t offset, const MutableBufferSequence& buffers,
     CompletionCondition completion_condition,
     ReadToken&& token = default_completion_token_t<
-      typename AsyncRandomAccessReadDevice::executor_type>())
+      typename AsyncRandomAccessReadDevice::executor_type>(),
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0)
   -> decltype(
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_at<AsyncRandomAccessReadDevice>>(),
         token, offset, buffers,
-        static_cast<CompletionCondition&&>(completion_condition)));
+        static_cast<CompletionCondition&&>(completion_condition)))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_at<AsyncRandomAccessReadDevice>(d),
+      token, offset, buffers,
+      static_cast<CompletionCondition&&>(completion_condition));
+}
 
 #if !defined(BOOST_ASIO_NO_EXTENSIONS)
 #if !defined(BOOST_ASIO_NO_IOSTREAM)
@@ -641,7 +672,7 @@ auto async_read_at(AsyncRandomAccessReadDevice& d,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -667,16 +698,25 @@ template <typename AsyncRandomAccessReadDevice, typename Allocator,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncRandomAccessReadDevice::executor_type>>
-auto async_read_at(AsyncRandomAccessReadDevice& d,
+inline auto async_read_at(AsyncRandomAccessReadDevice& d,
     uint64_t offset, basic_streambuf<Allocator>& b,
     ReadToken&& token = default_completion_token_t<
-      typename AsyncRandomAccessReadDevice::executor_type>())
+      typename AsyncRandomAccessReadDevice::executor_type>(),
+    constraint_t<
+      !is_completion_condition<ReadToken>::value
+    > = 0)
   -> decltype(
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_at_streambuf<
           AsyncRandomAccessReadDevice>>(),
-        token, offset, &b, transfer_all()));
+        token, offset, &b, transfer_all()))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_at_streambuf<AsyncRandomAccessReadDevice>(d),
+      token, offset, &b, transfer_all());
+}
 
 /// Start an asynchronous operation to read a certain amount of data at the
 /// specified offset.
@@ -732,7 +772,7 @@ auto async_read_at(AsyncRandomAccessReadDevice& d,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -753,17 +793,27 @@ template <typename AsyncRandomAccessReadDevice,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncRandomAccessReadDevice::executor_type>>
-auto async_read_at(AsyncRandomAccessReadDevice& d, uint64_t offset,
+inline auto async_read_at(AsyncRandomAccessReadDevice& d, uint64_t offset,
     basic_streambuf<Allocator>& b, CompletionCondition completion_condition,
     ReadToken&& token = default_completion_token_t<
-      typename AsyncRandomAccessReadDevice::executor_type>())
+      typename AsyncRandomAccessReadDevice::executor_type>(),
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0)
   -> decltype(
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_at_streambuf<
           AsyncRandomAccessReadDevice>>(),
         token, offset, &b,
-        static_cast<CompletionCondition&&>(completion_condition)));
+        static_cast<CompletionCondition&&>(completion_condition)))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_at_streambuf<AsyncRandomAccessReadDevice>(d),
+      token, offset, &b,
+      static_cast<CompletionCondition&&>(completion_condition));
+}
 
 #endif // !defined(BOOST_ASIO_NO_IOSTREAM)
 #endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/read_until.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/read_until.hpp
index 091a5424e2..0075c3220a 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/read_until.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/read_until.hpp
@@ -1603,7 +1603,7 @@ std::size_t read_until(SyncReadStream& s, DynamicBuffer_v2 buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1656,7 +1656,7 @@ template <typename AsyncReadStream, typename DynamicBuffer_v1,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read_until(AsyncReadStream& s,
+inline auto async_read_until(AsyncReadStream& s,
     DynamicBuffer_v1&& buffers, char delim,
     ReadToken&& token = default_completion_token_t<
       typename AsyncReadStream::executor_type>(),
@@ -1670,7 +1670,13 @@ auto async_read_until(AsyncReadStream& s,
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_until_delim_v1<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v1&&>(buffers), delim));
+        token, static_cast<DynamicBuffer_v1&&>(buffers), delim))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_until_delim_v1<AsyncReadStream>(s),
+      token, static_cast<DynamicBuffer_v1&&>(buffers), delim);
+}
 
 /// Start an asynchronous operation to read data into a dynamic buffer sequence
 /// until it contains a specified delimiter.
@@ -1720,7 +1726,7 @@ auto async_read_until(AsyncReadStream& s,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1773,7 +1779,7 @@ template <typename AsyncReadStream, typename DynamicBuffer_v1,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read_until(AsyncReadStream& s,
+inline auto async_read_until(AsyncReadStream& s,
     DynamicBuffer_v1&& buffers,
     BOOST_ASIO_STRING_VIEW_PARAM delim,
     ReadToken&& token = default_completion_token_t<
@@ -1790,7 +1796,14 @@ auto async_read_until(AsyncReadStream& s,
         declval<detail::initiate_async_read_until_delim_string_v1<
           AsyncReadStream>>(),
         token, static_cast<DynamicBuffer_v1&&>(buffers),
-        static_cast<std::string>(delim)));
+        static_cast<std::string>(delim)))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_until_delim_string_v1<AsyncReadStream>(s),
+      token, static_cast<DynamicBuffer_v1&&>(buffers),
+      static_cast<std::string>(delim));
+}
 
 #if !defined(BOOST_ASIO_NO_EXTENSIONS)
 #if defined(BOOST_ASIO_HAS_BOOST_REGEX) \
@@ -1848,7 +1861,7 @@ auto async_read_until(AsyncReadStream& s,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1902,7 +1915,7 @@ template <typename AsyncReadStream, typename DynamicBuffer_v1, typename Traits,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read_until(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
+inline auto async_read_until(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
     const boost::basic_regex<char, Traits>& expr,
     ReadToken&& token = default_completion_token_t<
       typename AsyncReadStream::executor_type>(),
@@ -1916,7 +1929,13 @@ auto async_read_until(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_until_expr_v1<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v1&&>(buffers), expr));
+        token, static_cast<DynamicBuffer_v1&&>(buffers), expr))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_until_expr_v1<AsyncReadStream>(s),
+      token, static_cast<DynamicBuffer_v1&&>(buffers), expr);
+}
 
 #endif // defined(BOOST_ASIO_HAS_BOOST_REGEX)
        // || defined(GENERATING_DOCUMENTATION)
@@ -1984,7 +2003,7 @@ auto async_read_until(AsyncReadStream& s, DynamicBuffer_v1&& buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @note After a successful async_read_until operation, the dynamic buffer
  * sequence may contain additional data beyond that which matched the function
@@ -2070,7 +2089,7 @@ template <typename AsyncReadStream,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read_until(AsyncReadStream& s,
+inline auto async_read_until(AsyncReadStream& s,
     DynamicBuffer_v1&& buffers, MatchCondition match_condition,
     ReadToken&& token = default_completion_token_t<
       typename AsyncReadStream::executor_type>(),
@@ -2088,7 +2107,14 @@ auto async_read_until(AsyncReadStream& s,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_until_match_v1<AsyncReadStream>>(),
         token, static_cast<DynamicBuffer_v1&&>(buffers),
-        match_condition));
+        match_condition))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_until_match_v1<AsyncReadStream>(s),
+      token, static_cast<DynamicBuffer_v1&&>(buffers),
+      match_condition);
+}
 
 #if !defined(BOOST_ASIO_NO_IOSTREAM)
 
@@ -2139,7 +2165,7 @@ auto async_read_until(AsyncReadStream& s,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -2191,7 +2217,7 @@ template <typename AsyncReadStream, typename Allocator,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read_until(AsyncReadStream& s,
+inline auto async_read_until(AsyncReadStream& s,
     boost::asio::basic_streambuf<Allocator>& b, char delim,
     ReadToken&& token = default_completion_token_t<
       typename AsyncReadStream::executor_type>())
@@ -2199,7 +2225,13 @@ auto async_read_until(AsyncReadStream& s,
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_until_delim_v1<AsyncReadStream>>(),
-        token, basic_streambuf_ref<Allocator>(b), delim));
+        token, basic_streambuf_ref<Allocator>(b), delim))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_until_delim_v1<AsyncReadStream>(s),
+      token, basic_streambuf_ref<Allocator>(b), delim);
+}
 
 /// Start an asynchronous operation to read data into a streambuf until it
 /// contains a specified delimiter.
@@ -2248,7 +2280,7 @@ auto async_read_until(AsyncReadStream& s,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -2300,7 +2332,7 @@ template <typename AsyncReadStream, typename Allocator,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read_until(AsyncReadStream& s,
+inline auto async_read_until(AsyncReadStream& s,
     boost::asio::basic_streambuf<Allocator>& b,
     BOOST_ASIO_STRING_VIEW_PARAM delim,
     ReadToken&& token = default_completion_token_t<
@@ -2311,7 +2343,14 @@ auto async_read_until(AsyncReadStream& s,
         declval<detail::initiate_async_read_until_delim_string_v1<
           AsyncReadStream>>(),
         token, basic_streambuf_ref<Allocator>(b),
-        static_cast<std::string>(delim)));
+        static_cast<std::string>(delim)))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_until_delim_string_v1<AsyncReadStream>(s),
+      token, basic_streambuf_ref<Allocator>(b),
+      static_cast<std::string>(delim));
+}
 
 #if defined(BOOST_ASIO_HAS_BOOST_REGEX) \
   || defined(GENERATING_DOCUMENTATION)
@@ -2365,7 +2404,7 @@ auto async_read_until(AsyncReadStream& s,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -2418,7 +2457,7 @@ template <typename AsyncReadStream, typename Allocator, typename Traits,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read_until(AsyncReadStream& s,
+inline auto async_read_until(AsyncReadStream& s,
     boost::asio::basic_streambuf<Allocator>& b,
     const boost::basic_regex<char, Traits>& expr,
     ReadToken&& token = default_completion_token_t<
@@ -2427,7 +2466,13 @@ auto async_read_until(AsyncReadStream& s,
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_until_expr_v1<AsyncReadStream>>(),
-        token, basic_streambuf_ref<Allocator>(b), expr));
+        token, basic_streambuf_ref<Allocator>(b), expr))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_until_expr_v1<AsyncReadStream>(s),
+      token, basic_streambuf_ref<Allocator>(b), expr);
+}
 
 #endif // defined(BOOST_ASIO_HAS_BOOST_REGEX)
        // || defined(GENERATING_DOCUMENTATION)
@@ -2492,7 +2537,7 @@ auto async_read_until(AsyncReadStream& s,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @note After a successful async_read_until operation, the streambuf may
  * contain additional data beyond that which matched the function object. An
@@ -2576,7 +2621,7 @@ template <typename AsyncReadStream, typename Allocator, typename MatchCondition,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read_until(AsyncReadStream& s,
+inline auto async_read_until(AsyncReadStream& s,
     boost::asio::basic_streambuf<Allocator>& b, MatchCondition match_condition,
     ReadToken&& token = default_completion_token_t<
       typename AsyncReadStream::executor_type>(),
@@ -2585,7 +2630,13 @@ auto async_read_until(AsyncReadStream& s,
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_until_match_v1<AsyncReadStream>>(),
-        token, basic_streambuf_ref<Allocator>(b), match_condition));
+        token, basic_streambuf_ref<Allocator>(b), match_condition))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_until_match_v1<AsyncReadStream>(s),
+      token, basic_streambuf_ref<Allocator>(b), match_condition);
+}
 
 #endif // !defined(BOOST_ASIO_NO_IOSTREAM)
 #endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
@@ -2640,7 +2691,7 @@ auto async_read_until(AsyncReadStream& s,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -2693,7 +2744,8 @@ template <typename AsyncReadStream, typename DynamicBuffer_v2,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read_until(AsyncReadStream& s, DynamicBuffer_v2 buffers, char delim,
+inline auto async_read_until(AsyncReadStream& s,
+    DynamicBuffer_v2 buffers, char delim,
     ReadToken&& token = default_completion_token_t<
       typename AsyncReadStream::executor_type>(),
     constraint_t<
@@ -2703,7 +2755,13 @@ auto async_read_until(AsyncReadStream& s, DynamicBuffer_v2 buffers, char delim,
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_until_delim_v2<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v2&&>(buffers), delim));
+        token, static_cast<DynamicBuffer_v2&&>(buffers), delim))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_until_delim_v2<AsyncReadStream>(s),
+      token, static_cast<DynamicBuffer_v2&&>(buffers), delim);
+}
 
 /// Start an asynchronous operation to read data into a dynamic buffer sequence
 /// until it contains a specified delimiter.
@@ -2753,7 +2811,7 @@ auto async_read_until(AsyncReadStream& s, DynamicBuffer_v2 buffers, char delim,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -2806,7 +2864,7 @@ template <typename AsyncReadStream, typename DynamicBuffer_v2,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read_until(AsyncReadStream& s, DynamicBuffer_v2 buffers,
+inline auto async_read_until(AsyncReadStream& s, DynamicBuffer_v2 buffers,
     BOOST_ASIO_STRING_VIEW_PARAM delim,
     ReadToken&& token = default_completion_token_t<
       typename AsyncReadStream::executor_type>(),
@@ -2819,7 +2877,14 @@ auto async_read_until(AsyncReadStream& s, DynamicBuffer_v2 buffers,
         declval<detail::initiate_async_read_until_delim_string_v2<
           AsyncReadStream>>(),
         token, static_cast<DynamicBuffer_v2&&>(buffers),
-        static_cast<std::string>(delim)));
+        static_cast<std::string>(delim)))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_until_delim_string_v2<AsyncReadStream>(s),
+      token, static_cast<DynamicBuffer_v2&&>(buffers),
+      static_cast<std::string>(delim));
+}
 
 #if !defined(BOOST_ASIO_NO_EXTENSIONS)
 #if defined(BOOST_ASIO_HAS_BOOST_REGEX) \
@@ -2877,7 +2942,7 @@ auto async_read_until(AsyncReadStream& s, DynamicBuffer_v2 buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -2931,7 +2996,7 @@ template <typename AsyncReadStream, typename DynamicBuffer_v2, typename Traits,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read_until(AsyncReadStream& s, DynamicBuffer_v2 buffers,
+inline auto async_read_until(AsyncReadStream& s, DynamicBuffer_v2 buffers,
     const boost::basic_regex<char, Traits>& expr,
     ReadToken&& token = default_completion_token_t<
       typename AsyncReadStream::executor_type>(),
@@ -2942,7 +3007,13 @@ auto async_read_until(AsyncReadStream& s, DynamicBuffer_v2 buffers,
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_until_expr_v2<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v2&&>(buffers), expr));
+        token, static_cast<DynamicBuffer_v2&&>(buffers), expr))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_until_expr_v2<AsyncReadStream>(s),
+      token, static_cast<DynamicBuffer_v2&&>(buffers), expr);
+}
 
 #endif // defined(BOOST_ASIO_HAS_BOOST_REGEX)
        // || defined(GENERATING_DOCUMENTATION)
@@ -3010,7 +3081,7 @@ auto async_read_until(AsyncReadStream& s, DynamicBuffer_v2 buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @note After a successful async_read_until operation, the dynamic buffer
  * sequence may contain additional data beyond that which matched the function
@@ -3096,7 +3167,7 @@ template <typename AsyncReadStream,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) ReadToken = default_completion_token_t<
         typename AsyncReadStream::executor_type>>
-auto async_read_until(AsyncReadStream& s,
+inline auto async_read_until(AsyncReadStream& s,
     DynamicBuffer_v2 buffers, MatchCondition match_condition,
     ReadToken&& token = default_completion_token_t<
       typename AsyncReadStream::executor_type>(),
@@ -3110,7 +3181,14 @@ auto async_read_until(AsyncReadStream& s,
     async_initiate<ReadToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_read_until_match_v2<AsyncReadStream>>(),
-        token, static_cast<DynamicBuffer_v2&&>(buffers), match_condition));
+        token, static_cast<DynamicBuffer_v2&&>(buffers), match_condition))
+{
+  return async_initiate<ReadToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_read_until_match_v2<AsyncReadStream>(s),
+      token, static_cast<DynamicBuffer_v2&&>(buffers),
+      match_condition);
+}
 
 #endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/redirect_error.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/redirect_error.hpp
index ac01bd856e..af62e2803d 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/redirect_error.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/redirect_error.hpp
@@ -34,7 +34,7 @@ template <typename CompletionToken>
 class redirect_error_t
 {
 public:
-  /// Constructor. 
+  /// Constructor.
   template <typename T>
   redirect_error_t(T&& completion_token, boost::system::error_code& ec)
     : token_(static_cast<T&&>(completion_token)),
@@ -47,10 +47,50 @@ class redirect_error_t
   boost::system::error_code& ec_;
 };
 
+/// A function object type that adapts a @ref completion_token to capture
+/// error_code values to a variable.
+/**
+ * May also be used directly as a completion token, in which case it adapts the
+ * asynchronous operation's default completion token (or boost::asio::deferred
+ * if no default is available).
+ */
+class partial_redirect_error
+{
+public:
+  /// Constructor that specifies the variable used to capture error_code values.
+  explicit partial_redirect_error(boost::system::error_code& ec)
+    : ec_(ec)
+  {
+  }
+
+  /// Adapt a @ref completion_token to specify that the completion handler
+  /// should capture error_code values to a variable.
+  template <typename CompletionToken>
+  BOOST_ASIO_NODISCARD inline
+  constexpr redirect_error_t<decay_t<CompletionToken>>
+  operator()(CompletionToken&& completion_token) const
+  {
+    return redirect_error_t<decay_t<CompletionToken>>(
+        static_cast<CompletionToken&&>(completion_token), ec_);
+  }
+
+//private:
+  boost::system::error_code& ec_;
+};
+
+/// Create a partial completion token adapter that captures error_code values
+/// to a variable.
+BOOST_ASIO_NODISCARD inline partial_redirect_error
+redirect_error(boost::system::error_code& ec)
+{
+  return partial_redirect_error(ec);
+}
+
 /// Adapt a @ref completion_token to capture error_code values to a variable.
 template <typename CompletionToken>
-inline redirect_error_t<decay_t<CompletionToken>> redirect_error(
-    CompletionToken&& completion_token, boost::system::error_code& ec)
+BOOST_ASIO_NODISCARD inline redirect_error_t<decay_t<CompletionToken>>
+redirect_error(CompletionToken&& completion_token,
+    boost::system::error_code& ec)
 {
   return redirect_error_t<decay_t<CompletionToken>>(
       static_cast<CompletionToken&&>(completion_token), ec);
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/registered_buffer.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/registered_buffer.hpp
index b2c78363cb..1396b20e70 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/registered_buffer.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/registered_buffer.hpp
@@ -79,7 +79,7 @@ class registered_buffer_id
 };
 
 /// Holds a registered buffer over modifiable data.
-/** 
+/**
  * Satisfies the @c MutableBufferSequence type requirements.
  */
 class mutable_registered_buffer
@@ -150,7 +150,7 @@ class mutable_registered_buffer
 };
 
 /// Holds a registered buffer over non-modifiable data.
-/** 
+/**
  * Satisfies the @c ConstBufferSequence type requirements.
  */
 class const_registered_buffer
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/spawn.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/spawn.hpp
index 765518e025..d7c508a4e4 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/spawn.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/spawn.hpp
@@ -146,7 +146,6 @@ class spawned_thread_base
   }
 };
 
-
 template <typename T>
 struct spawn_signature
 {
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/ssl/detail/impl/openssl_init.ipp b/src/cxx_supportlib/vendor-modified/boost/asio/ssl/detail/impl/openssl_init.ipp
index 23be3b6672..ea10e242fb 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/ssl/detail/impl/openssl_init.ipp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/ssl/detail/impl/openssl_init.ipp
@@ -38,7 +38,7 @@ public:
   {
 #if (OPENSSL_VERSION_NUMBER < 0x10100000L)
     ::SSL_library_init();
-    ::SSL_load_error_strings();        
+    ::SSL_load_error_strings();
     ::OpenSSL_add_all_algorithms();
 
     mutexes_.resize(::CRYPTO_num_locks());
@@ -124,7 +124,7 @@ private:
 #endif // (OPENSSL_VERSION_NUMBER < 0x10000000L)
 
 #if (OPENSSL_VERSION_NUMBER < 0x10100000L)
-  static void openssl_locking_func(int mode, int n, 
+  static void openssl_locking_func(int mode, int n,
     const char* /*file*/, int /*line*/)
   {
     if (mode & CRYPTO_LOCK)
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/ssl/impl/context.ipp b/src/cxx_supportlib/vendor-modified/boost/asio/ssl/impl/context.ipp
index 86f97447e1..3b1b7f5360 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/ssl/impl/context.ipp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/ssl/impl/context.ipp
@@ -270,8 +270,9 @@ context::context(context::method m)
 #endif // defined(SSL_TXT_TLSV1_2)
 
     // TLS v1.3.
-#if (OPENSSL_VERSION_NUMBER >= 0x10101000L) \
-    && !defined(LIBRESSL_VERSION_NUMBER)
+#if ((OPENSSL_VERSION_NUMBER >= 0x10101000L) \
+      && !defined(LIBRESSL_VERSION_NUMBER)) \
+    || defined(BOOST_ASIO_USE_WOLFSSL)
   case context::tlsv13:
     handle_ = ::SSL_CTX_new(::TLS_method());
     if (handle_)
@@ -296,16 +297,18 @@ context::context(context::method m)
       SSL_CTX_set_max_proto_version(handle_, TLS1_3_VERSION);
     }
     break;
-#else // (OPENSSL_VERSION_NUMBER >= 0x10101000L)
-      //   && !defined(LIBRESSL_VERSION_NUMBER)
+#else // ((OPENSSL_VERSION_NUMBER >= 0x10101000L)
+      //     && !defined(LIBRESSL_VERSION_NUMBER))
+      //   || defined(BOOST_ASIO_USE_WOLFSSL)
   case context::tlsv13:
   case context::tlsv13_client:
   case context::tlsv13_server:
     boost::asio::detail::throw_error(
         boost::asio::error::invalid_argument, "context");
     break;
-#endif // (OPENSSL_VERSION_NUMBER >= 0x10101000L)
-       //   && !defined(LIBRESSL_VERSION_NUMBER)
+#endif // ((OPENSSL_VERSION_NUMBER >= 0x10101000L)
+       //     && !defined(LIBRESSL_VERSION_NUMBER))
+       //   || defined(BOOST_ASIO_USE_WOLFSSL)
 
     // Any supported SSL/TLS version.
   case context::sslv23:
@@ -795,7 +798,7 @@ BOOST_ASIO_SYNC_OP_VOID context::use_certificate_chain(
         BOOST_ASIO_SYNC_OP_VOID_RETURN(ec);
       }
     }
-  
+
     result = ::ERR_peek_last_error();
     if ((ERR_GET_LIB(result) == ERR_LIB_PEM)
         && (ERR_GET_REASON(result) == PEM_R_NO_START_LINE))
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/ssl/stream.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/ssl/stream.hpp
index 30660c8a88..de2559beac 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/ssl/stream.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/ssl/stream.hpp
@@ -482,7 +482,7 @@ class stream :
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code) @endcode
@@ -539,7 +539,7 @@ class stream :
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -619,7 +619,7 @@ class stream :
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code) @endcode
@@ -723,7 +723,7 @@ class stream :
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
@@ -831,7 +831,7 @@ class stream :
    * Regardless of whether the asynchronous operation completes immediately or
    * not, the completion handler will not be invoked from within this function.
    * On immediate completion, invocation of the handler will be performed in a
-   * manner equivalent to using boost::asio::post().
+   * manner equivalent to using boost::asio::async_immediate().
    *
    * @par Completion Signature
    * @code void(boost::system::error_code, std::size_t) @endcode
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/this_coro.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/this_coro.hpp
index 936d360b6b..02accdf787 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/this_coro.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/this_coro.hpp
@@ -33,7 +33,7 @@ struct executor_t
 };
 
 /// Awaitable object that returns the executor of the current coroutine.
-constexpr executor_t executor;
+BOOST_ASIO_INLINE_VARIABLE constexpr executor_t executor;
 
 /// Awaitable type that returns the cancellation state of the current coroutine.
 struct cancellation_state_t
@@ -58,7 +58,7 @@ struct cancellation_state_t
  *     // ...
  * } @endcode
  */
-constexpr cancellation_state_t cancellation_state;
+BOOST_ASIO_INLINE_VARIABLE constexpr cancellation_state_t cancellation_state;
 
 #if defined(GENERATING_DOCUMENTATION)
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/use_awaitable.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/use_awaitable.hpp
index cbb8dc52cc..5e0e95a9c7 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/use_awaitable.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/use_awaitable.hpp
@@ -146,9 +146,9 @@ struct use_awaitable_t
  * See the documentation for boost::asio::use_awaitable_t for a usage example.
  */
 #if defined(GENERATING_DOCUMENTATION)
-constexpr use_awaitable_t<> use_awaitable;
+BOOST_ASIO_INLINE_VARIABLE constexpr use_awaitable_t<> use_awaitable;
 #else
-constexpr use_awaitable_t<> use_awaitable(0, 0, 0);
+BOOST_ASIO_INLINE_VARIABLE constexpr use_awaitable_t<> use_awaitable(0, 0, 0);
 #endif
 
 } // namespace asio
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/use_future.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/use_future.hpp
index 973bcfec6c..9f7bd777cf 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/use_future.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/use_future.hpp
@@ -146,7 +146,7 @@ class use_future_t
 /**
  * See the documentation for boost::asio::use_future_t for a usage example.
  */
-constexpr use_future_t<> use_future;
+BOOST_ASIO_INLINE_VARIABLE constexpr use_future_t<> use_future;
 
 } // namespace asio
 } // namespace boost
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/uses_executor.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/uses_executor.hpp
index 4105c3b2a4..d91f217811 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/uses_executor.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/uses_executor.hpp
@@ -46,7 +46,7 @@ struct executor_arg_t
  * See boost::asio::executor_arg_t and boost::asio::uses_executor
  * for more information.
  */
-constexpr executor_arg_t executor_arg;
+BOOST_ASIO_INLINE_VARIABLE constexpr executor_arg_t executor_arg;
 
 /// The uses_executor trait detects whether a type T has an associated executor
 /// that is convertible from type Executor.
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/version.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/version.hpp
index dbb6d2d8cb..671e1c60db 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/version.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/version.hpp
@@ -18,6 +18,6 @@
 // BOOST_ASIO_VERSION % 100 is the sub-minor version
 // BOOST_ASIO_VERSION / 100 % 1000 is the minor version
 // BOOST_ASIO_VERSION / 100000 is the major version
-#define BOOST_ASIO_VERSION 103002 // 1.30.2
+#define BOOST_ASIO_VERSION 103200 // 1.32.0
 
 #endif // BOOST_ASIO_VERSION_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/write.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/write.hpp
index 0fb866b5d5..9888f79db6 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/write.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/write.hpp
@@ -185,6 +185,9 @@ std::size_t write(SyncWriteStream& s, const ConstBufferSequence& buffers,
     CompletionCondition completion_condition,
     constraint_t<
       is_const_buffer_sequence<ConstBufferSequence>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0);
 
 /// Write a certain amount of data to a stream before returning.
@@ -232,6 +235,9 @@ std::size_t write(SyncWriteStream& s, const ConstBufferSequence& buffers,
     CompletionCondition completion_condition, boost::system::error_code& ec,
     constraint_t<
       is_const_buffer_sequence<ConstBufferSequence>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0);
 
 #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1)
@@ -357,6 +363,9 @@ std::size_t write(SyncWriteStream& s,
     > = 0,
     constraint_t<
       !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0);
 
 /// Write a certain amount of data to a stream before returning.
@@ -406,6 +415,9 @@ std::size_t write(SyncWriteStream& s,
     > = 0,
     constraint_t<
       !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0);
 
 #if !defined(BOOST_ASIO_NO_EXTENSIONS)
@@ -508,7 +520,10 @@ std::size_t write(SyncWriteStream& s, basic_streambuf<Allocator>& b,
 template <typename SyncWriteStream, typename Allocator,
     typename CompletionCondition>
 std::size_t write(SyncWriteStream& s, basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition);
+    CompletionCondition completion_condition,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0);
 
 /// Write a certain amount of data to a stream before returning.
 /**
@@ -549,7 +564,10 @@ std::size_t write(SyncWriteStream& s, basic_streambuf<Allocator>& b,
 template <typename SyncWriteStream, typename Allocator,
     typename CompletionCondition>
 std::size_t write(SyncWriteStream& s, basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition, boost::system::error_code& ec);
+    CompletionCondition completion_condition, boost::system::error_code& ec,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0);
 
 #endif // !defined(BOOST_ASIO_NO_IOSTREAM)
 #endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
@@ -664,6 +682,9 @@ std::size_t write(SyncWriteStream& s, DynamicBuffer_v2 buffers,
     CompletionCondition completion_condition,
     constraint_t<
       is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0);
 
 /// Write a certain amount of data to a stream before returning.
@@ -709,6 +730,9 @@ std::size_t write(SyncWriteStream& s, DynamicBuffer_v2 buffers,
     CompletionCondition completion_condition, boost::system::error_code& ec,
     constraint_t<
       is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0);
 
 /*@}*/
@@ -763,7 +787,7 @@ std::size_t write(SyncWriteStream& s, DynamicBuffer_v2 buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -792,17 +816,26 @@ template <typename AsyncWriteStream, typename ConstBufferSequence,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) WriteToken
         = default_completion_token_t<typename AsyncWriteStream::executor_type>>
-auto async_write(AsyncWriteStream& s, const ConstBufferSequence& buffers,
+inline auto async_write(AsyncWriteStream& s, const ConstBufferSequence& buffers,
     WriteToken&& token
       = default_completion_token_t<typename AsyncWriteStream::executor_type>(),
     constraint_t<
       is_const_buffer_sequence<ConstBufferSequence>::value
+    > = 0,
+    constraint_t<
+      !is_completion_condition<decay_t<WriteToken>>::value
     > = 0)
   -> decltype(
     async_initiate<WriteToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_write<AsyncWriteStream>>(),
-        token, buffers, transfer_all()));
+        token, buffers, transfer_all()))
+{
+  return async_initiate<WriteToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_write<AsyncWriteStream>(s),
+      token, buffers, transfer_all());
+}
 
 /// Start an asynchronous operation to write a certain amount of data to a
 /// stream.
@@ -861,7 +894,7 @@ auto async_write(AsyncWriteStream& s, const ConstBufferSequence& buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -890,19 +923,31 @@ auto async_write(AsyncWriteStream& s, const ConstBufferSequence& buffers,
 template <typename AsyncWriteStream,
     typename ConstBufferSequence, typename CompletionCondition,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-auto async_write(AsyncWriteStream& s, const ConstBufferSequence& buffers,
+      std::size_t)) WriteToken
+        = default_completion_token_t<typename AsyncWriteStream::executor_type>>
+inline auto async_write(AsyncWriteStream& s, const ConstBufferSequence& buffers,
     CompletionCondition completion_condition,
-    WriteToken&& token,
+    WriteToken&& token
+      = default_completion_token_t<typename AsyncWriteStream::executor_type>(),
     constraint_t<
       is_const_buffer_sequence<ConstBufferSequence>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0)
   -> decltype(
     async_initiate<WriteToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_write<AsyncWriteStream>>(),
         token, buffers,
-        static_cast<CompletionCondition&&>(completion_condition)));
+        static_cast<CompletionCondition&&>(completion_condition)))
+{
+  return async_initiate<WriteToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_write<AsyncWriteStream>(s),
+      token, buffers,
+      static_cast<CompletionCondition&&>(completion_condition));
+}
 
 #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1)
 
@@ -949,7 +994,7 @@ auto async_write(AsyncWriteStream& s, const ConstBufferSequence& buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -969,7 +1014,7 @@ template <typename AsyncWriteStream, typename DynamicBuffer_v1,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) WriteToken
         = default_completion_token_t<typename AsyncWriteStream::executor_type>>
-auto async_write(AsyncWriteStream& s, DynamicBuffer_v1&& buffers,
+inline auto async_write(AsyncWriteStream& s, DynamicBuffer_v1&& buffers,
     WriteToken&& token
       = default_completion_token_t<typename AsyncWriteStream::executor_type>(),
     constraint_t<
@@ -977,13 +1022,23 @@ auto async_write(AsyncWriteStream& s, DynamicBuffer_v1&& buffers,
     > = 0,
     constraint_t<
       !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
+    > = 0,
+    constraint_t<
+      !is_completion_condition<decay_t<WriteToken>>::value
     > = 0)
   -> decltype(
     async_initiate<WriteToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>>(),
         token, static_cast<DynamicBuffer_v1&&>(buffers),
-        transfer_all()));
+        transfer_all()))
+{
+  return async_initiate<WriteToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>(s),
+      token, static_cast<DynamicBuffer_v1&&>(buffers),
+      transfer_all());
+}
 
 /// Start an asynchronous operation to write a certain amount of data to a
 /// stream.
@@ -1042,7 +1097,7 @@ auto async_write(AsyncWriteStream& s, DynamicBuffer_v1&& buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1061,21 +1116,34 @@ auto async_write(AsyncWriteStream& s, DynamicBuffer_v1&& buffers,
 template <typename AsyncWriteStream,
     typename DynamicBuffer_v1, typename CompletionCondition,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-auto async_write(AsyncWriteStream& s, DynamicBuffer_v1&& buffers,
-    CompletionCondition completion_condition, WriteToken&& token,
+      std::size_t)) WriteToken
+        = default_completion_token_t<typename AsyncWriteStream::executor_type>>
+inline auto async_write(AsyncWriteStream& s, DynamicBuffer_v1&& buffers,
+    CompletionCondition completion_condition,
+    WriteToken&& token
+      = default_completion_token_t<typename AsyncWriteStream::executor_type>(),
     constraint_t<
       is_dynamic_buffer_v1<decay_t<DynamicBuffer_v1>>::value
     > = 0,
     constraint_t<
       !is_dynamic_buffer_v2<decay_t<DynamicBuffer_v1>>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0)
   -> decltype(
     async_initiate<WriteToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>>(),
         token, static_cast<DynamicBuffer_v1&&>(buffers),
-        static_cast<CompletionCondition&&>(completion_condition)));
+        static_cast<CompletionCondition&&>(completion_condition)))
+{
+  return async_initiate<WriteToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>(s),
+      token, static_cast<DynamicBuffer_v1&&>(buffers),
+      static_cast<CompletionCondition&&>(completion_condition));
+}
 
 #if !defined(BOOST_ASIO_NO_EXTENSIONS)
 #if !defined(BOOST_ASIO_NO_IOSTREAM)
@@ -1121,7 +1189,7 @@ auto async_write(AsyncWriteStream& s, DynamicBuffer_v1&& buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1141,14 +1209,23 @@ template <typename AsyncWriteStream, typename Allocator,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) WriteToken
         = default_completion_token_t<typename AsyncWriteStream::executor_type>>
-auto async_write(AsyncWriteStream& s, basic_streambuf<Allocator>& b,
+inline auto async_write(AsyncWriteStream& s, basic_streambuf<Allocator>& b,
     WriteToken&& token
-      = default_completion_token_t<typename AsyncWriteStream::executor_type>())
+      = default_completion_token_t<typename AsyncWriteStream::executor_type>(),
+    constraint_t<
+      !is_completion_condition<decay_t<WriteToken>>::value
+    > = 0)
   -> decltype(
     async_initiate<WriteToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>>(),
-        token, basic_streambuf_ref<Allocator>(b), transfer_all()));
+        token, basic_streambuf_ref<Allocator>(b), transfer_all()))
+{
+  return async_initiate<WriteToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>(s),
+      token, basic_streambuf_ref<Allocator>(b), transfer_all());
+}
 
 /// Start an asynchronous operation to write a certain amount of data to a
 /// stream.
@@ -1205,7 +1282,7 @@ auto async_write(AsyncWriteStream& s, basic_streambuf<Allocator>& b,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1224,15 +1301,28 @@ auto async_write(AsyncWriteStream& s, basic_streambuf<Allocator>& b,
 template <typename AsyncWriteStream,
     typename Allocator, typename CompletionCondition,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-auto async_write(AsyncWriteStream& s, basic_streambuf<Allocator>& b,
-    CompletionCondition completion_condition, WriteToken&& token)
+      std::size_t)) WriteToken
+        = default_completion_token_t<typename AsyncWriteStream::executor_type>>
+inline auto async_write(AsyncWriteStream& s, basic_streambuf<Allocator>& b,
+    CompletionCondition completion_condition,
+    WriteToken&& token
+      = default_completion_token_t<typename AsyncWriteStream::executor_type>(),
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0)
   -> decltype(
     async_initiate<WriteToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>>(),
         token, basic_streambuf_ref<Allocator>(b),
-        static_cast<CompletionCondition&&>(completion_condition)));
+        static_cast<CompletionCondition&&>(completion_condition)))
+{
+  return async_initiate<WriteToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_write_dynbuf_v1<AsyncWriteStream>(s),
+      token, basic_streambuf_ref<Allocator>(b),
+      static_cast<CompletionCondition&&>(completion_condition));
+}
 
 #endif // !defined(BOOST_ASIO_NO_IOSTREAM)
 #endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
@@ -1281,7 +1371,7 @@ auto async_write(AsyncWriteStream& s, basic_streambuf<Allocator>& b,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1301,18 +1391,28 @@ template <typename AsyncWriteStream, typename DynamicBuffer_v2,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) WriteToken
         = default_completion_token_t<typename AsyncWriteStream::executor_type>>
-auto async_write(AsyncWriteStream& s, DynamicBuffer_v2 buffers,
+inline auto async_write(AsyncWriteStream& s, DynamicBuffer_v2 buffers,
     WriteToken&& token
       = default_completion_token_t<typename AsyncWriteStream::executor_type>(),
     constraint_t<
       is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+    > = 0,
+    constraint_t<
+      !is_completion_condition<decay_t<WriteToken>>::value
     > = 0)
   -> decltype(
     async_initiate<WriteToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_write_dynbuf_v2<AsyncWriteStream>>(),
         token, static_cast<DynamicBuffer_v2&&>(buffers),
-        transfer_all()));
+        transfer_all()))
+{
+  return async_initiate<WriteToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_write_dynbuf_v2<AsyncWriteStream>(s),
+      token, static_cast<DynamicBuffer_v2&&>(buffers),
+      transfer_all());
+}
 
 /// Start an asynchronous operation to write a certain amount of data to a
 /// stream.
@@ -1371,7 +1471,7 @@ auto async_write(AsyncWriteStream& s, DynamicBuffer_v2 buffers,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -1390,19 +1490,31 @@ auto async_write(AsyncWriteStream& s, DynamicBuffer_v2 buffers,
 template <typename AsyncWriteStream,
     typename DynamicBuffer_v2, typename CompletionCondition,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
-      std::size_t)) WriteToken>
-auto async_write(AsyncWriteStream& s, DynamicBuffer_v2 buffers,
+      std::size_t)) WriteToken
+        = default_completion_token_t<typename AsyncWriteStream::executor_type>>
+inline auto async_write(AsyncWriteStream& s, DynamicBuffer_v2 buffers,
     CompletionCondition completion_condition,
-    WriteToken&& token,
+    WriteToken&& token
+      = default_completion_token_t<typename AsyncWriteStream::executor_type>(),
     constraint_t<
       is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+    > = 0,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
     > = 0)
   -> decltype(
     async_initiate<WriteToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_write_dynbuf_v2<AsyncWriteStream>>(),
         token, static_cast<DynamicBuffer_v2&&>(buffers),
-        static_cast<CompletionCondition&&>(completion_condition)));
+        static_cast<CompletionCondition&&>(completion_condition)))
+{
+  return async_initiate<WriteToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_write_dynbuf_v2<AsyncWriteStream>(s),
+      token, static_cast<DynamicBuffer_v2&&>(buffers),
+      static_cast<CompletionCondition&&>(completion_condition));
+}
 
 /*@}*/
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/asio/write_at.hpp b/src/cxx_supportlib/vendor-modified/boost/asio/write_at.hpp
index 9c17a58118..504a2d1e97 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio/write_at.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio/write_at.hpp
@@ -188,7 +188,10 @@ template <typename SyncRandomAccessWriteDevice, typename ConstBufferSequence,
     typename CompletionCondition>
 std::size_t write_at(SyncRandomAccessWriteDevice& d,
     uint64_t offset, const ConstBufferSequence& buffers,
-    CompletionCondition completion_condition);
+    CompletionCondition completion_condition,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0);
 
 /// Write a certain amount of data at a specified offset before returning.
 /**
@@ -236,7 +239,10 @@ template <typename SyncRandomAccessWriteDevice, typename ConstBufferSequence,
     typename CompletionCondition>
 std::size_t write_at(SyncRandomAccessWriteDevice& d,
     uint64_t offset, const ConstBufferSequence& buffers,
-    CompletionCondition completion_condition, boost::system::error_code& ec);
+    CompletionCondition completion_condition, boost::system::error_code& ec,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0);
 
 #if !defined(BOOST_ASIO_NO_EXTENSIONS)
 #if !defined(BOOST_ASIO_NO_IOSTREAM)
@@ -349,7 +355,10 @@ std::size_t write_at(SyncRandomAccessWriteDevice& d,
 template <typename SyncRandomAccessWriteDevice, typename Allocator,
     typename CompletionCondition>
 std::size_t write_at(SyncRandomAccessWriteDevice& d, uint64_t offset,
-    basic_streambuf<Allocator>& b, CompletionCondition completion_condition);
+    basic_streambuf<Allocator>& b, CompletionCondition completion_condition,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0);
 
 /// Write a certain amount of data at a specified offset before returning.
 /**
@@ -392,9 +401,12 @@ std::size_t write_at(SyncRandomAccessWriteDevice& d, uint64_t offset,
  */
 template <typename SyncRandomAccessWriteDevice, typename Allocator,
     typename CompletionCondition>
-std::size_t write_at(SyncRandomAccessWriteDevice& d, uint64_t offset,
-    basic_streambuf<Allocator>& b, CompletionCondition completion_condition,
-    boost::system::error_code& ec);
+std::size_t write_at(SyncRandomAccessWriteDevice& d,
+    uint64_t offset, basic_streambuf<Allocator>& b,
+    CompletionCondition completion_condition, boost::system::error_code& ec,
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0);
 
 #endif // !defined(BOOST_ASIO_NO_IOSTREAM)
 #endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
@@ -457,7 +469,7 @@ std::size_t write_at(SyncRandomAccessWriteDevice& d, uint64_t offset,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -486,16 +498,25 @@ template <typename AsyncRandomAccessWriteDevice, typename ConstBufferSequence,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) WriteToken = default_completion_token_t<
         typename AsyncRandomAccessWriteDevice::executor_type>>
-auto async_write_at(AsyncRandomAccessWriteDevice& d,
+inline auto async_write_at(AsyncRandomAccessWriteDevice& d,
     uint64_t offset, const ConstBufferSequence& buffers,
     WriteToken&& token = default_completion_token_t<
-      typename AsyncRandomAccessWriteDevice::executor_type>())
+      typename AsyncRandomAccessWriteDevice::executor_type>(),
+    constraint_t<
+      !is_completion_condition<WriteToken>::value
+    > = 0)
   -> decltype(
     async_initiate<WriteToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_write_at<
           AsyncRandomAccessWriteDevice>>(),
-        token, offset, buffers, transfer_all()));
+        token, offset, buffers, transfer_all()))
+{
+  return async_initiate<WriteToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_write_at<AsyncRandomAccessWriteDevice>(d),
+      token, offset, buffers, transfer_all());
+}
 
 /// Start an asynchronous operation to write a certain amount of data at the
 /// specified offset.
@@ -559,7 +580,7 @@ auto async_write_at(AsyncRandomAccessWriteDevice& d,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -590,18 +611,28 @@ template <typename AsyncRandomAccessWriteDevice,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) WriteToken = default_completion_token_t<
         typename AsyncRandomAccessWriteDevice::executor_type>>
-auto async_write_at(AsyncRandomAccessWriteDevice& d,
+inline auto async_write_at(AsyncRandomAccessWriteDevice& d,
     uint64_t offset, const ConstBufferSequence& buffers,
     CompletionCondition completion_condition,
     WriteToken&& token = default_completion_token_t<
-      typename AsyncRandomAccessWriteDevice::executor_type>())
+      typename AsyncRandomAccessWriteDevice::executor_type>(),
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0)
   -> decltype(
     async_initiate<WriteToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_write_at<
           AsyncRandomAccessWriteDevice>>(),
         token, offset, buffers,
-        static_cast<CompletionCondition&&>(completion_condition)));
+        static_cast<CompletionCondition&&>(completion_condition)))
+{
+  return async_initiate<WriteToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_write_at<AsyncRandomAccessWriteDevice>(d),
+      token, offset, buffers,
+      static_cast<CompletionCondition&&>(completion_condition));
+}
 
 #if !defined(BOOST_ASIO_NO_EXTENSIONS)
 #if !defined(BOOST_ASIO_NO_IOSTREAM)
@@ -652,7 +683,7 @@ auto async_write_at(AsyncRandomAccessWriteDevice& d,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -672,16 +703,26 @@ template <typename AsyncRandomAccessWriteDevice, typename Allocator,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) WriteToken = default_completion_token_t<
         typename AsyncRandomAccessWriteDevice::executor_type>>
-auto async_write_at(AsyncRandomAccessWriteDevice& d,
+inline auto async_write_at(AsyncRandomAccessWriteDevice& d,
     uint64_t offset, basic_streambuf<Allocator>& b,
     WriteToken&& token = default_completion_token_t<
-      typename AsyncRandomAccessWriteDevice::executor_type>())
+      typename AsyncRandomAccessWriteDevice::executor_type>(),
+    constraint_t<
+      !is_completion_condition<WriteToken>::value
+    > = 0)
   -> decltype(
     async_initiate<WriteToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_write_at_streambuf<
           AsyncRandomAccessWriteDevice>>(),
-        token, offset, &b, transfer_all()));
+        token, offset, &b, transfer_all()))
+{
+  return async_initiate<WriteToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_write_at_streambuf<
+        AsyncRandomAccessWriteDevice>(d),
+      token, offset, &b, transfer_all());
+}
 
 /// Start an asynchronous operation to write a certain amount of data at the
 /// specified offset.
@@ -743,7 +784,7 @@ auto async_write_at(AsyncRandomAccessWriteDevice& d,
  * Regardless of whether the asynchronous operation completes immediately or
  * not, the completion handler will not be invoked from within this function.
  * On immediate completion, invocation of the handler will be performed in a
- * manner equivalent to using boost::asio::post().
+ * manner equivalent to using boost::asio::async_immediate().
  *
  * @par Completion Signature
  * @code void(boost::system::error_code, std::size_t) @endcode
@@ -764,17 +805,28 @@ template <typename AsyncRandomAccessWriteDevice,
     BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
       std::size_t)) WriteToken = default_completion_token_t<
         typename AsyncRandomAccessWriteDevice::executor_type>>
-auto async_write_at(AsyncRandomAccessWriteDevice& d, uint64_t offset,
+inline auto async_write_at(AsyncRandomAccessWriteDevice& d, uint64_t offset,
     basic_streambuf<Allocator>& b, CompletionCondition completion_condition,
     WriteToken&& token = default_completion_token_t<
-      typename AsyncRandomAccessWriteDevice::executor_type>())
+      typename AsyncRandomAccessWriteDevice::executor_type>(),
+    constraint_t<
+      is_completion_condition<CompletionCondition>::value
+    > = 0)
   -> decltype(
     async_initiate<WriteToken,
       void (boost::system::error_code, std::size_t)>(
         declval<detail::initiate_async_write_at_streambuf<
           AsyncRandomAccessWriteDevice>>(),
         token, offset, &b,
-        static_cast<CompletionCondition&&>(completion_condition)));
+        static_cast<CompletionCondition&&>(completion_condition)))
+{
+  return async_initiate<WriteToken,
+    void (boost::system::error_code, std::size_t)>(
+      detail::initiate_async_write_at_streambuf<
+        AsyncRandomAccessWriteDevice>(d),
+      token, offset, &b,
+      static_cast<CompletionCondition&&>(completion_condition));
+}
 
 #endif // !defined(BOOST_ASIO_NO_IOSTREAM)
 #endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
diff --git a/src/cxx_supportlib/vendor-modified/boost/assert/source_location.hpp b/src/cxx_supportlib/vendor-modified/boost/assert/source_location.hpp
index c4d5f1b173..c6eae32515 100644
--- a/src/cxx_supportlib/vendor-modified/boost/assert/source_location.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/assert/source_location.hpp
@@ -174,9 +174,12 @@ template<class E, class T> std::basic_ostream<E, T> & operator<<( std::basic_ost
 
 # define BOOST_CURRENT_LOCATION ::boost::source_location(__builtin_FILE(), __builtin_LINE(), __builtin_FUNCTION(), __builtin_COLUMN())
 
-#elif defined(BOOST_GCC) && BOOST_GCC >= 70000
+#elif defined(BOOST_GCC) && BOOST_GCC >= 80000
 
 // The built-ins are available in 4.8+, but are not constant expressions until 7
+// In addition, reproducible builds require -ffile-prefix-map, which is GCC 8
+// https://github.com/boostorg/assert/issues/38
+
 # define BOOST_CURRENT_LOCATION ::boost::source_location(__builtin_FILE(), __builtin_LINE(), __builtin_FUNCTION())
 
 #elif defined(BOOST_GCC) && BOOST_GCC >= 50000
diff --git a/src/cxx_supportlib/vendor-modified/boost/atomic/detail/futex.hpp b/src/cxx_supportlib/vendor-modified/boost/atomic/detail/futex.hpp
index f5cb98922d..55407ed846 100644
--- a/src/cxx_supportlib/vendor-modified/boost/atomic/detail/futex.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/atomic/detail/futex.hpp
@@ -23,7 +23,7 @@
 #pragma once
 #endif
 
-#if defined(__linux__) || defined(__OpenBSD__) || defined(__NETBSD__) || defined(__NetBSD__)
+#if defined(__linux__) || defined(__NETBSD__) || defined(__NetBSD__)
 
 #include <sys/syscall.h>
 
@@ -45,7 +45,21 @@
 #define BOOST_ATOMIC_DETAIL_NETBSD_FUTEX
 #endif
 
-#if defined(BOOST_ATOMIC_DETAIL_SYS_FUTEX)
+#elif defined(__OpenBSD__)
+
+// OpenBSD provides futex(2) function wrapper since OpenBSD 6.2 (https://man.openbsd.org/OpenBSD-6.2/futex.2).
+// It has also removed syscall(2) interface:
+// https://github.com/openbsd/src/commit/cafeb892b121ee89c39c2b940e8ccd6950f50009
+
+#include <sys/param.h>
+
+#if OpenBSD >= 201711
+#define BOOST_ATOMIC_DETAIL_OPENBSD_FUTEX
+#endif
+
+#endif
+
+#if defined(BOOST_ATOMIC_DETAIL_SYS_FUTEX) || defined(BOOST_ATOMIC_DETAIL_OPENBSD_FUTEX)
 
 #include <cstddef>
 #if defined(__linux__)
@@ -53,6 +67,7 @@
 #else
 #include <sys/futex.h>
 #endif
+#include <boost/cstdint.hpp>
 #include <boost/atomic/detail/intptr.hpp>
 #include <boost/atomic/detail/header.hpp>
 
@@ -74,22 +89,40 @@ namespace detail {
 //! Invokes an operation on the futex
 BOOST_FORCEINLINE int futex_invoke(void* addr1, int op, unsigned int val1, const void* timeout = NULL, void* addr2 = NULL, unsigned int val3 = 0) BOOST_NOEXCEPT
 {
-#if !defined(BOOST_ATOMIC_DETAIL_NETBSD_FUTEX)
-    return ::syscall(BOOST_ATOMIC_DETAIL_SYS_FUTEX, addr1, op, val1, timeout, addr2, val3);
-#else
+#if defined(BOOST_ATOMIC_DETAIL_OPENBSD_FUTEX)
+    return ::futex
+    (
+        static_cast< volatile uint32_t* >(addr1),
+        op,
+        static_cast< int >(val1),
+        static_cast< const struct timespec* >(timeout),
+        static_cast< volatile uint32_t* >(addr2)
+    );
+#elif defined(BOOST_ATOMIC_DETAIL_NETBSD_FUTEX)
     // Pass 0 in val2.
     return ::syscall(BOOST_ATOMIC_DETAIL_SYS_FUTEX, addr1, op, val1, timeout, addr2, 0u, val3);
+#else
+    return ::syscall(BOOST_ATOMIC_DETAIL_SYS_FUTEX, addr1, op, val1, timeout, addr2, val3);
 #endif
 }
 
 //! Invokes an operation on the futex
 BOOST_FORCEINLINE int futex_invoke(void* addr1, int op, unsigned int val1, unsigned int val2, void* addr2 = NULL, unsigned int val3 = 0) BOOST_NOEXCEPT
 {
-#if !defined(BOOST_ATOMIC_DETAIL_NETBSD_FUTEX)
-    return ::syscall(BOOST_ATOMIC_DETAIL_SYS_FUTEX, addr1, op, val1, static_cast< atomics::detail::uintptr_t >(val2), addr2, val3);
-#else
+#if defined(BOOST_ATOMIC_DETAIL_OPENBSD_FUTEX)
+    return ::futex
+    (
+        static_cast< volatile uint32_t* >(addr1),
+        op,
+        static_cast< int >(val1),
+        reinterpret_cast< const struct timespec* >(static_cast< atomics::detail::uintptr_t >(val2)),
+        static_cast< volatile uint32_t* >(addr2)
+    );
+#elif defined(BOOST_ATOMIC_DETAIL_NETBSD_FUTEX)
     // Pass NULL in timeout.
     return ::syscall(BOOST_ATOMIC_DETAIL_SYS_FUTEX, addr1, op, val1, static_cast< void* >(NULL), addr2, val2, val3);
+#else
+    return ::syscall(BOOST_ATOMIC_DETAIL_SYS_FUTEX, addr1, op, val1, static_cast< atomics::detail::uintptr_t >(val2), addr2, val3);
 #endif
 }
 
@@ -147,8 +180,6 @@ BOOST_FORCEINLINE int futex_requeue_private(void* pval1, void* pval2, unsigned i
 
 #include <boost/atomic/detail/footer.hpp>
 
-#endif // defined(BOOST_ATOMIC_DETAIL_SYS_FUTEX)
-
-#endif // defined(__linux__) || defined(__OpenBSD__) || defined(__NETBSD__) || defined(__NetBSD__)
+#endif // defined(BOOST_ATOMIC_DETAIL_SYS_FUTEX) || defined(BOOST_ATOMIC_DETAIL_OPENBSD_FUTEX)
 
 #endif // BOOST_ATOMIC_DETAIL_FUTEX_HPP_INCLUDED_
diff --git a/src/cxx_supportlib/vendor-modified/boost/bind/bind.hpp b/src/cxx_supportlib/vendor-modified/boost/bind/bind.hpp
index 2d5b454e90..5ec7923090 100644
--- a/src/cxx_supportlib/vendor-modified/boost/bind/bind.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/bind/bind.hpp
@@ -737,44 +737,18 @@ template<class F, class... A>
 namespace _bi
 {
 
-template< class Pm, int I > struct add_cref;
+template<class M, int I> struct add_cref;
 
-template< class M, class T > struct add_cref< M T::*, 0 >
+template<class M> struct add_cref<M, 0>
 {
     typedef M type;
 };
 
-template< class M, class T > struct add_cref< M T::*, 1 >
+template<class M> struct add_cref<M, 1>
 {
-#ifdef BOOST_MSVC
-#pragma warning(push)
-#pragma warning(disable:4180)
-#endif
-    typedef M const & type;
-#ifdef BOOST_MSVC
-#pragma warning(pop)
-#endif
-};
-
-template< class R, class T > struct add_cref< R (T::*) (), 1 >
-{
-    typedef void type;
-};
-
-template< class R, class T > struct add_cref< R (T::*) () const, 1 >
-{
-    typedef void type;
-};
-
-#if defined( __cpp_noexcept_function_type ) || defined( _NOEXCEPT_TYPES_SUPPORTED )
-
-template< class R, class T > struct add_cref< R (T::*) () const noexcept, 1 >
-{
-    typedef void type;
+    typedef M const& type;
 };
 
-#endif // __cpp_noexcept_function_type
-
 template<class R> struct isref
 {
     enum value_type { value = 0 };
@@ -790,30 +764,34 @@ template<class R> struct isref< R* >
     enum value_type { value = 1 };
 };
 
-template<class Pm, class A1> struct dm_result
+template<class M, class A1, bool fn = std::is_function<M>::value> struct dm_result
+{
+};
+
+template<class M, class A1> struct dm_result<M, A1, false>
 {
-    typedef typename add_cref< Pm, 1 >::type type;
+    typedef typename add_cref< M, 1 >::type type;
 };
 
-template<class Pm, class R, class F, class L> struct dm_result< Pm, bind_t<R, F, L> >
+template<class M, class R, class F, class L> struct dm_result<M, bind_t<R, F, L>, false>
 {
     typedef typename bind_t<R, F, L>::result_type result_type;
-    typedef typename add_cref< Pm, isref< result_type >::value >::type type;
+    typedef typename add_cref< M, isref< result_type >::value >::type type;
 };
 
 } // namespace _bi
 
-template< class A1, class M, class T >
+template<class A1, class M, class T>
 
 _bi::bind_t<
-    typename _bi::dm_result< M T::*, A1 >::type,
+    typename _bi::dm_result<M, A1>::type,
     _mfi::dm<M, T>,
     typename _bi::list_av<A1>::type
 >
 
 BOOST_BIND( M T::*f, A1 a1 )
 {
-    typedef typename _bi::dm_result< M T::*, A1 >::type result_type;
+    typedef typename _bi::dm_result<M, A1>::type result_type;
     typedef _mfi::dm<M, T> F;
     typedef typename _bi::list_av<A1>::type list_type;
     return _bi::bind_t< result_type, F, list_type >( F( f ), list_type( a1 ) );
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/adaptive_pool.hpp b/src/cxx_supportlib/vendor-modified/boost/container/adaptive_pool.hpp
index 9b10cb47fa..a6a89fa592 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/adaptive_pool.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/adaptive_pool.hpp
@@ -71,10 +71,10 @@ class adaptive_pool
          BOOST_CONTAINER_DOCIGN(BOOST_MOVE_I Version)
          >   self_t;
 
-   static const std::size_t nodes_per_block        = NodesPerBlock;
-   static const std::size_t max_free_blocks        = MaxFreeBlocks;
-   static const std::size_t overhead_percent       = OverheadPercent;
-   static const std::size_t real_nodes_per_block   = NodesPerBlock;
+   BOOST_STATIC_CONSTEXPR std::size_t nodes_per_block        = NodesPerBlock;
+   BOOST_STATIC_CONSTEXPR std::size_t max_free_blocks        = MaxFreeBlocks;
+   BOOST_STATIC_CONSTEXPR std::size_t overhead_percent       = OverheadPercent;
+   BOOST_STATIC_CONSTEXPR std::size_t real_nodes_per_block   = NodesPerBlock;
 
    BOOST_CONTAINER_DOCIGN(BOOST_CONTAINER_STATIC_ASSERT((Version <=2)));
 
@@ -384,10 +384,10 @@ class private_adaptive_pool
          BOOST_CONTAINER_DOCIGN(BOOST_MOVE_I Version)
          >   self_t;
 
-   static const std::size_t nodes_per_block        = NodesPerBlock;
-   static const std::size_t max_free_blocks        = MaxFreeBlocks;
-   static const std::size_t overhead_percent       = OverheadPercent;
-   static const std::size_t real_nodes_per_block   = NodesPerBlock;
+   BOOST_STATIC_CONSTEXPR std::size_t nodes_per_block        = NodesPerBlock;
+   BOOST_STATIC_CONSTEXPR std::size_t max_free_blocks        = MaxFreeBlocks;
+   BOOST_STATIC_CONSTEXPR std::size_t overhead_percent       = OverheadPercent;
+   BOOST_STATIC_CONSTEXPR std::size_t real_nodes_per_block   = NodesPerBlock;
 
    BOOST_CONTAINER_DOCIGN(BOOST_CONTAINER_STATIC_ASSERT((Version <=2)));
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/allocator.hpp b/src/cxx_supportlib/vendor-modified/boost/container/allocator.hpp
index 33c2a8a414..68a158c0ee 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/allocator.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/allocator.hpp
@@ -115,7 +115,7 @@ class allocator
    template<class T2, unsigned int Version2, unsigned int AllocationDisableMask2>
    allocator& operator=(const allocator<T2, Version2, AllocationDisableMask2>&);
 
-   static const unsigned int ForbiddenMask =
+   BOOST_STATIC_CONSTEXPR unsigned int ForbiddenMask =
       BOOST_CONTAINER_ALLOCATE_NEW | BOOST_CONTAINER_EXPAND_BWD | BOOST_CONTAINER_EXPAND_FWD ;
 
    //The mask can't disable all the allocation types
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/allocator_traits.hpp b/src/cxx_supportlib/vendor-modified/boost/container/allocator_traits.hpp
index cdb6683e88..dd5bf0e42d 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/allocator_traits.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/allocator_traits.hpp
@@ -32,6 +32,8 @@
 #include <boost/container/detail/mpl.hpp>
 #include <boost/container/detail/type_traits.hpp>  //is_empty
 #include <boost/container/detail/placement_new.hpp>
+#include <boost/container/detail/is_pair.hpp>
+#include <boost/container/detail/addressof.hpp>
 #ifndef BOOST_CONTAINER_DETAIL_STD_FWD_HPP
 #include <boost/container/detail/std_fwd.hpp>
 #endif
@@ -47,9 +49,10 @@
 
 #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
 
-#if defined(BOOST_GCC) && (BOOST_GCC >= 40600)
+#if defined(BOOST_CONTAINER_GCC_COMPATIBLE_HAS_DIAGNOSTIC_IGNORED)
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wunused-result"
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 #endif
 
 #define BOOST_INTRUSIVE_HAS_MEMBER_FUNCTION_CALLABLE_WITH_FUNCNAME allocate
@@ -73,7 +76,7 @@
 #define BOOST_INTRUSIVE_HAS_MEMBER_FUNCTION_CALLABLE_WITH_MAX 9
 #include <boost/intrusive/detail/has_member_function_callable_with.hpp>
 
-#if defined(BOOST_GCC) && (BOOST_GCC >= 40600)
+#if defined(BOOST_CONTAINER_GCC_COMPATIBLE_HAS_DIAGNOSTIC_IGNORED)
 #pragma GCC diagnostic pop
 #endif
 
@@ -81,6 +84,144 @@
 
 namespace boost {
 namespace container {
+namespace dtl {
+
+#if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
+
+template<class T, class ...Args>
+BOOST_CONTAINER_FORCEINLINE void construct_type(T *p, BOOST_FWD_REF(Args) ...args)
+{
+   ::new((void*)p, boost_container_new_t()) T(::boost::forward<Args>(args)...);
+}
+
+template < class Pair, class KeyType, class ... Args>
+typename dtl::enable_if< dtl::is_pair<Pair>, void >::type
+construct_type
+   (Pair* p, try_emplace_t, BOOST_FWD_REF(KeyType) k, BOOST_FWD_REF(Args) ...args)
+{
+   construct_type(dtl::addressof(p->first), ::boost::forward<KeyType>(k));
+   BOOST_CONTAINER_TRY{
+      construct_type(dtl::addressof(p->second), ::boost::forward<Args>(args)...);
+   }
+   BOOST_CONTAINER_CATCH(...) {
+      typedef typename Pair::first_type first_type;
+      dtl::addressof(p->first)->~first_type();
+      BOOST_CONTAINER_RETHROW
+   }
+   BOOST_CONTAINER_CATCH_END
+}
+
+#else
+
+#define BOOST_CONTAINER_ALLOCATOR_TRAITS_CONSTRUCT_TYPEJ(N) \
+template<class T BOOST_MOVE_I##N BOOST_MOVE_CLASS##N>\
+BOOST_CONTAINER_FORCEINLINE \
+   typename dtl::disable_if_c<dtl::is_pair<T>::value, void >::type \
+construct_type(T *p BOOST_MOVE_I##N BOOST_MOVE_UREF##N)\
+{\
+   ::new((void*)p, boost_container_new_t()) T( BOOST_MOVE_FWD##N );\
+}\
+//
+BOOST_MOVE_ITERATE_0TO8(BOOST_CONTAINER_ALLOCATOR_TRAITS_CONSTRUCT_TYPEJ)
+#undef BOOST_CONTAINER_ALLOCATOR_TRAITS_CONSTRUCT_TYPEJ
+
+#define BOOST_CONTAINER_ALLOCATOR_TRAITS_CONSTRUCT_TYPE(N) \
+template < class Pair, class KeyType BOOST_MOVE_I##N BOOST_MOVE_CLASS##N>\
+typename dtl::enable_if< dtl::is_pair<Pair>, void >::type construct_type\
+   (Pair* p, try_emplace_t, BOOST_FWD_REF(KeyType) k BOOST_MOVE_I##N BOOST_MOVE_UREF##N)\
+{\
+   construct_type(dtl::addressof(p->first), ::boost::forward<KeyType>(k));\
+   BOOST_CONTAINER_TRY{\
+      construct_type(dtl::addressof(p->second) BOOST_MOVE_I##N BOOST_MOVE_FWD##N);\
+   }\
+   BOOST_CONTAINER_CATCH(...) {\
+      typedef typename Pair::first_type first_type;\
+      dtl::addressof(p->first)->~first_type();\
+      BOOST_CONTAINER_RETHROW\
+   }\
+   BOOST_CONTAINER_CATCH_END\
+}\
+//
+BOOST_MOVE_ITERATE_0TO8(BOOST_CONTAINER_ALLOCATOR_TRAITS_CONSTRUCT_TYPE)
+#undef BOOST_CONTAINER_ALLOCATOR_TRAITS_CONSTRUCT_TYPE
+
+#endif
+
+template<class T>
+inline
+typename dtl::enable_if<dtl::is_pair<T>, void >::type
+construct_type(T* p)
+{
+   dtl::construct_type(dtl::addressof(p->first));
+   BOOST_CONTAINER_TRY{
+      dtl::construct_type(dtl::addressof(p->second));
+   }
+   BOOST_CONTAINER_CATCH(...) {
+      typedef typename T::first_type first_type;
+      dtl::addressof(p->first)->~first_type();
+      BOOST_CONTAINER_RETHROW
+   }
+   BOOST_CONTAINER_CATCH_END
+}
+
+
+template<class T, class U>
+inline
+typename dtl::enable_if_c
+   <  dtl::is_pair<T>::value
+   , void >::type
+construct_type(T* p, U &u)
+{
+   dtl::construct_type(dtl::addressof(p->first), u.first);
+   BOOST_CONTAINER_TRY{
+      dtl::construct_type(dtl::addressof(p->second), u.second);
+   }
+   BOOST_CONTAINER_CATCH(...) {
+      typedef typename T::first_type first_type;
+      dtl::addressof(p->first)->~first_type();
+      BOOST_CONTAINER_RETHROW
+   }
+   BOOST_CONTAINER_CATCH_END
+}
+
+template<class T, class U>
+inline
+typename dtl::enable_if_c
+   <  dtl::is_pair<typename dtl::remove_reference<T>::type>::value &&
+      !boost::move_detail::is_reference<U>::value  //This is needed for MSVC10 and ambiguous overloads
+   , void >::type
+construct_type(T* p, BOOST_RV_REF(U) u)
+{
+   dtl::construct_type(dtl::addressof(p->first), ::boost::move(u.first));
+   BOOST_CONTAINER_TRY{
+      dtl::construct_type(dtl::addressof(p->second), ::boost::move(u.second));
+   }
+   BOOST_CONTAINER_CATCH(...) {
+      typedef typename T::first_type first_type;
+      dtl::addressof(p->first)->~first_type();
+      BOOST_CONTAINER_RETHROW
+   }
+   BOOST_CONTAINER_CATCH_END
+}
+
+template<class T, class U, class V>
+inline
+typename dtl::enable_if<dtl::is_pair<T>, void >::type
+construct_type(T* p, BOOST_FWD_REF(U) x, BOOST_FWD_REF(V) y)
+{
+   dtl::construct_type(dtl::addressof(p->first), ::boost::forward<U>(x));
+   BOOST_CONTAINER_TRY{
+      dtl::construct_type(dtl::addressof(p->second), ::boost::forward<V>(y));
+   }
+   BOOST_CONTAINER_CATCH(...) {
+      typedef typename T::first_type first_type;
+      dtl::addressof(p->first)->~first_type();
+      BOOST_CONTAINER_RETHROW
+   }
+   BOOST_CONTAINER_CATCH_END
+}
+
+}  //namespace dtl
 
 #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
 
@@ -100,19 +241,19 @@ namespace dtl {
 //supporting rvalue references
 template<class Allocator>
 struct is_std_allocator
-{  static const bool value = false; };
+{  BOOST_STATIC_CONSTEXPR bool value = false; };
 
 template<class T>
 struct is_std_allocator< std::allocator<T> >
-{  static const bool value = true; };
+{  BOOST_STATIC_CONSTEXPR bool value = true; };
 
 template<class T, class Options>
 struct is_std_allocator< small_vector_allocator<T, std::allocator<T>, Options > >
-{  static const bool value = true; };
+{  BOOST_STATIC_CONSTEXPR bool value = true; };
 
 template<class Allocator>
 struct is_not_std_allocator
-{  static const bool value = !is_std_allocator<Allocator>::value; };
+{  BOOST_STATIC_CONSTEXPR bool value = !is_std_allocator<Allocator>::value; };
 
 BOOST_INTRUSIVE_INSTANTIATE_DEFAULT_TYPE_TMPLT(pointer)
 BOOST_INTRUSIVE_INSTANTIATE_EVAL_DEFAULT_TYPE_TMPLT(const_pointer)
@@ -358,7 +499,7 @@ struct allocator_traits
       template <class T, class ...Args>
       inline static void construct(Allocator & a, T* p, BOOST_FWD_REF(Args)... args)
       {
-         static const bool value = ::boost::move_detail::and_
+         BOOST_STATIC_CONSTEXPR bool value = ::boost::move_detail::and_
             < dtl::is_not_std_allocator<Allocator>
             , boost::container::dtl::has_member_function_callable_with_construct
                   < Allocator, T*, Args... >
@@ -419,7 +560,7 @@ struct allocator_traits
 
       template<class T, class ...Args>
       inline static void priv_construct(dtl::false_type, Allocator &, T *p, BOOST_FWD_REF(Args) ...args)
-      {  ::new((void*)p, boost_container_new_t()) T(::boost::forward<Args>(args)...); }
+      {  dtl::construct_type(p, ::boost::forward<Args>(args)...); }
    #else // #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
       public:
 
@@ -427,7 +568,7 @@ struct allocator_traits
       template<class T BOOST_MOVE_I##N BOOST_MOVE_CLASS##N >\
       inline static void construct(Allocator &a, T *p BOOST_MOVE_I##N BOOST_MOVE_UREF##N)\
       {\
-         static const bool value = ::boost::move_detail::and_ \
+         BOOST_STATIC_CONSTEXPR bool value = ::boost::move_detail::and_ \
             < dtl::is_not_std_allocator<Allocator> \
             , boost::container::dtl::has_member_function_callable_with_construct \
                   < Allocator, T* BOOST_MOVE_I##N BOOST_MOVE_FWD_T##N > \
@@ -450,7 +591,7 @@ struct allocator_traits
       \
       template<class T BOOST_MOVE_I##N BOOST_MOVE_CLASS##N >\
       inline static void priv_construct(dtl::false_type, Allocator &, T *p BOOST_MOVE_I##N BOOST_MOVE_UREF##N)\
-      {  ::new((void*)p, boost_container_new_t()) T(BOOST_MOVE_FWD##N); }\
+      {  dtl::construct_type(p BOOST_MOVE_I##N BOOST_MOVE_FWD##N); }\
       //
       BOOST_MOVE_ITERATE_0TO8(BOOST_CONTAINER_ALLOCATOR_TRAITS_PRIV_CONSTRUCT_IMPL)
       #undef BOOST_CONTAINER_ALLOCATOR_TRAITS_PRIV_CONSTRUCT_IMPL
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/container_fwd.hpp b/src/cxx_supportlib/vendor-modified/boost/container/container_fwd.hpp
index 9e82fdef66..2525b7d28f 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/container_fwd.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/container_fwd.hpp
@@ -15,6 +15,8 @@
 #  include <boost/config.hpp>
 #endif
 
+#include <boost/container/detail/workaround.hpp>
+
 #if defined(BOOST_HAS_PRAGMA_ONCE)
 #  pragma once
 #endif
@@ -277,10 +279,10 @@ class basic_string;
 typedef basic_string <char>   string;
 typedef basic_string<wchar_t> wstring;
 
-static const std::size_t ADP_nodes_per_block    = 256u;
-static const std::size_t ADP_max_free_blocks    = 2u;
-static const std::size_t ADP_overhead_percent   = 1u;
-static const std::size_t ADP_only_alignment     = 0u;
+BOOST_STATIC_CONSTEXPR std::size_t ADP_nodes_per_block    = 256u;
+BOOST_STATIC_CONSTEXPR std::size_t ADP_max_free_blocks    = 2u;
+BOOST_STATIC_CONSTEXPR std::size_t ADP_overhead_percent   = 1u;
+BOOST_STATIC_CONSTEXPR std::size_t ADP_only_alignment     = 0u;
 
 template < class T
          , std::size_t NodesPerBlock   = ADP_nodes_per_block
@@ -295,7 +297,7 @@ template < class T
          , unsigned int AllocationDisableMask = 0>
 class allocator;
 
-static const std::size_t NodeAlloc_nodes_per_block = 256u;
+BOOST_STATIC_CONSTEXPR std::size_t NodeAlloc_nodes_per_block = 256u;
 
 template
    < class T
@@ -332,7 +334,7 @@ struct ordered_range_t
 
 //! Value used to tag that the input range is
 //! guaranteed to be ordered
-static const ordered_range_t ordered_range = ordered_range_t();
+BOOST_CONTAINER_CONSTANT_VAR ordered_range_t ordered_range = ordered_range_t();
 
 //! Type used to tag that the input range is
 //! guaranteed to be ordered and unique
@@ -342,7 +344,7 @@ struct ordered_unique_range_t
 
 //! Value used to tag that the input range is
 //! guaranteed to be ordered and unique
-static const ordered_unique_range_t ordered_unique_range = ordered_unique_range_t();
+BOOST_CONTAINER_CONSTANT_VAR ordered_unique_range_t ordered_unique_range = ordered_unique_range_t();
 
 //! Type used to tag that the inserted values
 //! should be default initialized
@@ -351,7 +353,7 @@ struct default_init_t
 
 //! Value used to tag that the inserted values
 //! should be default initialized
-static const default_init_t default_init = default_init_t();
+BOOST_CONTAINER_CONSTANT_VAR default_init_t default_init = default_init_t();
 #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
 
 //! Type used to tag that the inserted values
@@ -361,7 +363,7 @@ struct value_init_t
 
 //! Value used to tag that the inserted values
 //! should be value initialized
-static const value_init_t value_init = value_init_t();
+BOOST_CONTAINER_CONSTANT_VAR value_init_t value_init = value_init_t();
 
 namespace container_detail_really_deep_namespace {
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/deque.hpp b/src/cxx_supportlib/vendor-modified/boost/container/deque.hpp
index 157c900f65..da24ad0d75 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/deque.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/deque.hpp
@@ -68,16 +68,16 @@ template <class T>
 struct deque_value_traits
 {
    typedef T value_type;
-   static const bool trivial_dctr = dtl::is_trivially_destructible<value_type>::value;
-   static const bool trivial_dctr_after_move = ::boost::has_trivial_destructor_after_move<value_type>::value;
+   BOOST_STATIC_CONSTEXPR bool trivial_dctr = dtl::is_trivially_destructible<value_type>::value;
+   BOOST_STATIC_CONSTEXPR bool trivial_dctr_after_move = ::boost::has_trivial_destructor_after_move<value_type>::value;
 };
 
 template<class T, std::size_t BlockBytes, std::size_t BlockSize>
 struct deque_block_size
 {
    BOOST_CONTAINER_STATIC_ASSERT_MSG(!(BlockBytes && BlockSize), "BlockBytes and BlockSize can't be specified at the same time");
-   static const std::size_t block_bytes = BlockBytes ? BlockBytes : 512u;
-   static const std::size_t value       = BlockSize ? BlockSize : (sizeof(T) < block_bytes ? (block_bytes/sizeof(T)) : std::size_t(1));
+   BOOST_STATIC_CONSTEXPR std::size_t block_bytes = BlockBytes ? BlockBytes : 512u;
+   BOOST_STATIC_CONSTEXPR std::size_t value       = BlockSize ? BlockSize : (sizeof(T) < block_bytes ? (block_bytes/sizeof(T)) : std::size_t(1));
 };
 
 namespace dtl {
@@ -106,6 +106,10 @@ namespace dtl {
 //    [map, map + map_size).
 //  A pointer in the range [map, map + map_size) points to an allocated node
 //    if and only if the pointer is in the range [start.node, finish.node].
+
+#define BOOST_CONTAINER_DEQUE_LIGHTER_ITERATOR_LEVEL 0
+
+#if BOOST_CONTAINER_DEQUE_LIGHTER_ITERATOR_LEVEL == 0
 template<class Pointer, bool IsConst>
 class deque_iterator
 {
@@ -241,15 +245,15 @@ class deque_iterator
       if (!n)
          return *this;
       BOOST_ASSERT(!!m_cur);
-      difference_type offset = n + (this->m_cur - this->m_first);
+      const difference_type offset = n + (this->m_cur - this->m_first);
       const difference_type block_size = m_last - m_first;
       BOOST_ASSERT(block_size);
       if (offset >= 0 && offset < block_size)
          this->m_cur += difference_type(n);
       else {
-         difference_type node_offset =
-         offset > 0 ? (offset / block_size)
-                    : (-difference_type((-offset - 1) / block_size) - 1);
+         const difference_type node_offset =
+            offset > 0 ? (offset / block_size)
+                       : (-difference_type((-offset - 1) / block_size) - 1);
          this->priv_set_node(this->m_node + node_offset, size_type(block_size));
          this->m_cur = this->m_first +
          (offset - node_offset * block_size);
@@ -313,6 +317,447 @@ class deque_iterator
    }
 };
 
+#elif BOOST_CONTAINER_DEQUE_LIGHTER_ITERATOR_LEVEL == 1
+
+template<class Pointer, bool IsConst, unsigned BlockBytes, unsigned BlockSize>
+class deque_iterator
+{
+   public:
+   typedef std::random_access_iterator_tag                                          iterator_category;
+   typedef typename boost::intrusive::pointer_traits<Pointer>::element_type         value_type;
+   typedef typename boost::intrusive::pointer_traits<Pointer>::difference_type      difference_type;
+   typedef typename boost::intrusive::pointer_traits<Pointer>::size_type            size_type;
+   typedef typename if_c
+      < IsConst
+      , typename boost::intrusive::pointer_traits<Pointer>::template
+                                 rebind_pointer<const value_type>::type
+      , Pointer
+      >::type                                                                       pointer;
+   typedef typename if_c
+      < IsConst
+      , const value_type&
+      , value_type&
+      >::type                                                                       reference;
+
+   BOOST_CONSTEXPR inline static size_type get_block_size() BOOST_NOEXCEPT_OR_NOTHROW
+      { return deque_block_size<value_type, BlockBytes, BlockSize>::value; }
+
+   BOOST_CONSTEXPR inline static difference_type get_block_ssize() BOOST_NOEXCEPT_OR_NOTHROW
+      { return difference_type((get_block_size())); }
+
+   class nat;
+   typedef typename dtl::if_c< IsConst
+                             , deque_iterator<Pointer, false, BlockBytes, BlockSize>
+                             , nat>::type                                           nonconst_iterator;
+
+   typedef Pointer                                                                  val_alloc_ptr;
+   typedef typename boost::intrusive::pointer_traits<Pointer>::
+      template rebind_pointer<Pointer>::type                                        index_pointer;
+
+   Pointer m_cur;
+   Pointer m_first;
+   index_pointer  m_node;
+
+   public:
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline Pointer get_cur()          const  {  return m_cur;  }
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline Pointer get_first()        const  {  return m_first;  }
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline Pointer get_last()         const  { return m_first + get_block_ssize(); }
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline index_pointer get_node()   const  {  return m_node;  }
+
+   inline deque_iterator(val_alloc_ptr x, index_pointer y, difference_type ) BOOST_NOEXCEPT_OR_NOTHROW
+      : m_cur(x), m_first(*y), m_node(y)
+   {}
+
+   inline deque_iterator(val_alloc_ptr x, index_pointer y, size_type ) BOOST_NOEXCEPT_OR_NOTHROW
+      : m_cur(x), m_first(*y), m_node(y)
+   {}
+
+   inline deque_iterator() BOOST_NOEXCEPT_OR_NOTHROW
+      : m_cur(), m_first(), m_node()  //Value initialization to achieve "null iterators" (N3644)
+   {}
+
+   inline deque_iterator(const deque_iterator& x) BOOST_NOEXCEPT_OR_NOTHROW
+      : m_cur(x.get_cur()), m_first(x.get_first()), m_node(x.get_node())
+   {}
+
+   inline deque_iterator(const nonconst_iterator& x) BOOST_NOEXCEPT_OR_NOTHROW
+      : m_cur(x.get_cur()), m_first(x.get_first()), m_node(x.get_node())
+   {}
+
+   inline deque_iterator(Pointer cur, Pointer first, index_pointer node) BOOST_NOEXCEPT_OR_NOTHROW
+      : m_cur(cur), m_first(first), m_node(node)
+   {}
+
+   inline deque_iterator& operator=(const deque_iterator& x) BOOST_NOEXCEPT_OR_NOTHROW
+   {  m_cur = x.get_cur(); m_first = x.get_first(); m_node = x.get_node(); return *this; }
+
+   inline nonconst_iterator unconst() const BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      return nonconst_iterator(this->get_cur(), this->get_first(), this->get_node());
+   }
+
+   inline reference operator*() const BOOST_NOEXCEPT_OR_NOTHROW
+      { return *this->m_cur; }
+
+   inline pointer operator->() const BOOST_NOEXCEPT_OR_NOTHROW
+      { return this->m_cur; }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD difference_type operator-(const deque_iterator& x) const BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      if(!this->m_cur && !x.m_cur){
+         return 0;
+      }
+      const difference_type block_size = get_block_ssize();
+      BOOST_ASSERT(block_size);
+      return block_size * (this->m_node - x.m_node - 1) +
+         (this->m_cur - this->m_first) + ((x.m_first+block_size) - x.m_cur);
+   }
+
+   deque_iterator& operator++() BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      BOOST_ASSERT(!!m_cur);
+      ++this->m_cur;
+      const difference_type block_size = get_block_ssize();
+      if (this->m_cur == (this->m_first+block_size)) {
+
+         BOOST_ASSERT(block_size);
+         ++this->m_node;
+         this->m_first = *this->m_node;
+         this->m_cur = this->m_first;
+      }
+      return *this;
+   }
+
+   inline deque_iterator operator++(int) BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      deque_iterator tmp(*this);
+      ++*this;
+      return tmp;
+   }
+
+   deque_iterator& operator--() BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      BOOST_ASSERT(!!m_cur);
+      if (this->m_cur == this->m_first) {
+         --this->m_node;
+         this->m_first = *this->m_node;
+         this->m_cur = this->m_first + get_block_ssize();
+      }
+      --this->m_cur;
+      return *this;
+   }
+
+   inline deque_iterator operator--(int) BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      deque_iterator tmp(*this);
+      --*this;
+      return tmp;
+   }
+
+   deque_iterator& operator+=(difference_type n) BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      if (!n)
+         return *this;
+      BOOST_ASSERT(!!m_cur);
+      const difference_type offset = n + (this->m_cur - this->m_first);
+      const difference_type block_size = get_block_ssize();
+      BOOST_ASSERT(block_size);
+      if (offset >= 0 && offset < block_size)
+         this->m_cur += difference_type(n);
+      else {
+         const difference_type node_offset =
+            offset > 0 ? (offset / block_size)
+                       : (-difference_type((-offset - 1) / block_size) - 1);
+         this->m_node += node_offset;
+         this->m_first = *this->m_node;
+         this->m_cur = this->m_first + (offset - node_offset * block_size);
+      }
+      return *this;
+   }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      deque_iterator operator+(difference_type n) const BOOST_NOEXCEPT_OR_NOTHROW
+      {  deque_iterator tmp(*this); return tmp += n;  }
+
+   inline
+      deque_iterator& operator-=(difference_type n) BOOST_NOEXCEPT_OR_NOTHROW
+      { return *this += -n; }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      deque_iterator operator-(difference_type n) const BOOST_NOEXCEPT_OR_NOTHROW
+      {  deque_iterator tmp(*this); return tmp -= n;  }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      reference operator[](difference_type n) const BOOST_NOEXCEPT_OR_NOTHROW
+      { return *(*this + n); }
+
+   //Comparisons
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      friend bool operator==(const deque_iterator& l, const deque_iterator& r) BOOST_NOEXCEPT_OR_NOTHROW
+      { return l.m_cur == r.m_cur; }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      friend bool operator!=(const deque_iterator& l, const deque_iterator& r) BOOST_NOEXCEPT_OR_NOTHROW
+      { return l.m_cur != r.m_cur; }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      friend bool operator<(const deque_iterator& l, const deque_iterator& r) BOOST_NOEXCEPT_OR_NOTHROW
+      {  return (l.m_node == r.m_node) ? (l.m_cur < r.m_cur) : (l.m_node < r.m_node);  }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      friend bool operator>(const deque_iterator& l, const deque_iterator& r) BOOST_NOEXCEPT_OR_NOTHROW
+      { return r < l; }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      friend bool operator<=(const deque_iterator& l, const deque_iterator& r) BOOST_NOEXCEPT_OR_NOTHROW
+      { return !(r < l); }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      friend bool operator>=(const deque_iterator& l, const deque_iterator& r) BOOST_NOEXCEPT_OR_NOTHROW
+      { return !(l < r); }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      friend deque_iterator operator+(difference_type n, deque_iterator x) BOOST_NOEXCEPT_OR_NOTHROW
+      {  return x += n;  }
+
+   inline void priv_set_node(index_pointer new_node, size_type ) BOOST_NOEXCEPT_OR_NOTHROW
+   {  return this->priv_set_node(new_node, difference_type()); }
+
+   inline void priv_set_node(index_pointer new_node, difference_type) BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      this->m_node = new_node;
+      this->m_first = *new_node;
+   }
+};
+
+#elif BOOST_CONTAINER_DEQUE_LIGHTER_ITERATOR_LEVEL == 2
+
+template<class Pointer, bool IsConst, unsigned BlockBytes, unsigned BlockSize>
+class deque_iterator
+{
+   public:
+   typedef std::random_access_iterator_tag                                          iterator_category;
+   typedef typename boost::intrusive::pointer_traits<Pointer>::element_type         value_type;
+   typedef typename boost::intrusive::pointer_traits<Pointer>::difference_type      difference_type;
+   typedef typename boost::intrusive::pointer_traits<Pointer>::size_type            size_type;
+   typedef typename if_c
+      < IsConst
+      , typename boost::intrusive::pointer_traits<Pointer>::template
+                                 rebind_pointer<const value_type>::type
+      , Pointer
+      >::type                                                                       pointer;
+   typedef typename if_c
+      < IsConst
+      , const value_type&
+      , value_type&
+      >::type                                                                       reference;
+
+   BOOST_CONSTEXPR inline static size_type get_block_size() BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      BOOST_CONTAINER_STATIC_ASSERT((deque_block_size<value_type, BlockBytes, BlockSize>::value));
+      return deque_block_size<value_type, BlockBytes, BlockSize>::value;
+   }
+
+   BOOST_CONSTEXPR inline static difference_type get_block_ssize() BOOST_NOEXCEPT_OR_NOTHROW
+      { return difference_type((get_block_size())); }
+
+   class nat;
+   typedef typename dtl::if_c< IsConst
+                             , deque_iterator<Pointer, false, BlockBytes, BlockSize>
+                             , nat>::type                                           nonconst_iterator;
+
+   typedef Pointer                                                                  val_alloc_ptr;
+   typedef typename boost::intrusive::pointer_traits<Pointer>::
+      template rebind_pointer<Pointer>::type                                        index_pointer;
+
+   Pointer m_cur;
+   index_pointer  m_node;
+
+   public:
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline Pointer get_cur()          const  {  return m_cur;  }
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline Pointer get_first()        const  {  return *m_node;  }
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline Pointer get_last()         const  { return *m_node + get_block_ssize(); }
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline index_pointer get_node()   const  {  return m_node;  }
+
+   inline deque_iterator(val_alloc_ptr x, index_pointer y, difference_type ) BOOST_NOEXCEPT_OR_NOTHROW
+      : m_cur(x), m_node(y)
+   {}
+
+   inline deque_iterator(val_alloc_ptr x, index_pointer y, size_type ) BOOST_NOEXCEPT_OR_NOTHROW
+      : m_cur(x), m_node(y)
+   {}
+
+   inline deque_iterator() BOOST_NOEXCEPT_OR_NOTHROW
+      : m_cur(), m_node()  //Value initialization to achieve "null iterators" (N3644)
+   {}
+
+   inline deque_iterator(const deque_iterator& x) BOOST_NOEXCEPT_OR_NOTHROW
+      : m_cur(x.get_cur()), m_node(x.get_node())
+   {}
+
+   inline deque_iterator(const nonconst_iterator& x) BOOST_NOEXCEPT_OR_NOTHROW
+      : m_cur(x.get_cur()), m_node(x.get_node())
+   {}
+
+   inline deque_iterator(Pointer cur, index_pointer node) BOOST_NOEXCEPT_OR_NOTHROW
+      : m_cur(cur), m_node(node)
+   {}
+
+   inline deque_iterator& operator=(const deque_iterator& x) BOOST_NOEXCEPT_OR_NOTHROW
+   {  m_cur = x.get_cur(); m_node = x.get_node(); return *this; }
+
+   inline nonconst_iterator unconst() const BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      return nonconst_iterator(this->get_cur(), this->get_node());
+   }
+
+   inline reference operator*() const BOOST_NOEXCEPT_OR_NOTHROW
+      { return *this->m_cur; }
+
+   inline pointer operator->() const BOOST_NOEXCEPT_OR_NOTHROW
+      { return this->m_cur; }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD difference_type operator-(const deque_iterator& x) const BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      if(!this->m_cur && !x.m_cur){
+         return 0;
+      }
+      const difference_type block_size = get_block_ssize();
+      BOOST_ASSERT(block_size);
+      return block_size * (this->m_node - x.m_node - 1) +
+         (this->m_cur - this->get_first()) + (x.get_last() - x.m_cur);
+   }
+
+   deque_iterator& operator++() BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      BOOST_ASSERT(!!m_cur);
+      ++this->m_cur;
+      if (this->m_cur == (this->get_last())) {
+
+         ++this->m_node;
+         this->m_cur = *this->m_node;
+      }
+      return *this;
+   }
+
+   inline deque_iterator operator++(int) BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      deque_iterator tmp(*this);
+      ++*this;
+      return tmp;
+   }
+
+   deque_iterator& operator--() BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      BOOST_ASSERT(!!m_cur);
+      if (this->m_cur == this->get_first()) {
+         --this->m_node;
+         this->m_cur = this->get_last();
+      }
+      --this->m_cur;
+      return *this;
+   }
+
+   inline deque_iterator operator--(int) BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      deque_iterator tmp(*this);
+      --*this;
+      return tmp;
+   }
+
+   deque_iterator& operator+=(difference_type n) BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      if (!n)
+         return *this;
+      BOOST_ASSERT(!!m_cur);
+      const difference_type offset = n + (this->m_cur - this->get_first());
+      const difference_type block_size = get_block_ssize();
+      BOOST_ASSERT(block_size);
+      if (offset >= 0 && offset < block_size)
+         this->m_cur += difference_type(n);
+      else {
+         const difference_type node_offset =
+            offset > 0 ? (offset / block_size)
+                       : (-difference_type((-offset - 1) / block_size) - 1);
+         this->m_node += node_offset;
+         this->m_cur = this->get_first() + (offset - node_offset * block_size);
+      }
+      return *this;
+   }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      deque_iterator operator+(difference_type n) const BOOST_NOEXCEPT_OR_NOTHROW
+      {  deque_iterator tmp(*this); return tmp += n;  }
+
+   inline
+      deque_iterator& operator-=(difference_type n) BOOST_NOEXCEPT_OR_NOTHROW
+      { return *this += -n; }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      deque_iterator operator-(difference_type n) const BOOST_NOEXCEPT_OR_NOTHROW
+      {  deque_iterator tmp(*this); return tmp -= n;  }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      reference operator[](difference_type n) const BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      BOOST_ASSERT(!!m_cur);
+      const difference_type offset = n + (this->m_cur - this->get_first());
+      const difference_type block_size = get_block_ssize();
+      if (offset >= 0 && offset < block_size)
+         return this->m_cur[difference_type(n)];
+      else {
+         const difference_type node_offset = offset > 0
+            ? (offset / block_size)
+            : (-difference_type((-offset - 1) / block_size) - 1);
+         return (this->m_node[node_offset]) [offset - node_offset * block_size];
+      }
+   }
+
+   //Comparisons
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      friend bool operator==(const deque_iterator& l, const deque_iterator& r) BOOST_NOEXCEPT_OR_NOTHROW
+      { return l.m_cur == r.m_cur; }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      friend bool operator!=(const deque_iterator& l, const deque_iterator& r) BOOST_NOEXCEPT_OR_NOTHROW
+      { return l.m_cur != r.m_cur; }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      friend bool operator<(const deque_iterator& l, const deque_iterator& r) BOOST_NOEXCEPT_OR_NOTHROW
+      {  return (l.m_node == r.m_node) ? (l.m_cur < r.m_cur) : (l.m_node < r.m_node);  }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      friend bool operator>(const deque_iterator& l, const deque_iterator& r) BOOST_NOEXCEPT_OR_NOTHROW
+      { return r < l; }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      friend bool operator<=(const deque_iterator& l, const deque_iterator& r) BOOST_NOEXCEPT_OR_NOTHROW
+      { return !(r < l); }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      friend bool operator>=(const deque_iterator& l, const deque_iterator& r) BOOST_NOEXCEPT_OR_NOTHROW
+      { return !(l < r); }
+
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      friend deque_iterator operator+(difference_type n, deque_iterator x) BOOST_NOEXCEPT_OR_NOTHROW
+      {  return x += n;  }
+
+   inline void priv_set_node(index_pointer new_node, size_type ) BOOST_NOEXCEPT_OR_NOTHROW
+   {  return this->priv_set_node(new_node, difference_type()); }
+
+   inline void priv_set_node(index_pointer new_node, difference_type) BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      this->m_node = new_node;
+   }
+};
+
+#else
+
+#error "Invalid BOOST_CONTAINER_DEQUE_LIGHTER_ITERATOR_LEVEL"
+
+#endif
 }  //namespace dtl {
 
 template<class Options>
@@ -360,15 +805,20 @@ class deque_base
    typedef typename get_deque_opt<Options>::type                  options_type;
 
    protected:
+   #if BOOST_CONTAINER_DEQUE_LIGHTER_ITERATOR_LEVEL == 0
    typedef dtl::deque_iterator<val_alloc_ptr, false> iterator;
-   typedef dtl::deque_iterator<val_alloc_ptr, true > const_iterator;
+   typedef dtl::deque_iterator<val_alloc_ptr, true> const_iterator;
+   #else
+   typedef dtl::deque_iterator<val_alloc_ptr, false, options_type::block_bytes, options_type::block_size> iterator;
+   typedef dtl::deque_iterator<val_alloc_ptr, true, options_type::block_bytes, options_type::block_size> const_iterator;
+   #endif
+
+   BOOST_CONSTEXPR inline static val_alloc_diff get_block_ssize() BOOST_NOEXCEPT_OR_NOTHROW
+      { return val_alloc_diff((get_block_size())); }
 
    BOOST_CONSTEXPR inline static size_type get_block_size() BOOST_NOEXCEPT_OR_NOTHROW
       { return deque_block_size<val_alloc_val, options_type::block_bytes, options_type::block_size>::value; }
 
-   BOOST_CONSTEXPR inline static val_alloc_diff get_block_ssize() BOOST_NOEXCEPT_OR_NOTHROW
-      { return val_alloc_diff((get_block_size)()); }
-
    typedef deque_value_traits<val_alloc_val>             traits_t;
    typedef ptr_alloc_t                                   map_allocator_type;
 
@@ -446,8 +896,8 @@ class deque_base
 
          this->members_.m_start.priv_set_node(nstart, get_block_size());
          this->members_.m_finish.priv_set_node(nfinish - 1, get_block_size());
-         this->members_.m_start.m_cur = this->members_.m_start.m_first;
-         this->members_.m_finish.m_cur = this->members_.m_finish.m_first + difference_type(num_elements % get_block_size());
+         this->members_.m_start.m_cur = this->members_.m_start.get_first();
+         this->members_.m_finish.m_cur = this->members_.m_finish.get_first() + difference_type(num_elements % get_block_size());
 //      }
    }
 
@@ -868,28 +1318,13 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
                                   || allocator_traits_type::is_always_equal::value)
    {
       if (BOOST_LIKELY(this != &x)) {
-         allocator_type &this_alloc = this->alloc();
-         allocator_type &x_alloc    = x.alloc();
-         const bool propagate_alloc = allocator_traits_type::
-               propagate_on_container_move_assignment::value;
-         dtl::bool_<propagate_alloc> flag;
-         const bool allocators_equal = this_alloc == x_alloc; (void)allocators_equal;
-         //Resources can be transferred if both allocators are
-         //going to be equal after this function (either propagated or already equal)
-         if(propagate_alloc || allocators_equal){
-            //Destroy objects but retain memory in case x reuses it in the future
-            this->clear();
-            //Move allocator if needed
-            dtl::move_alloc(this_alloc, x_alloc, flag);
-            dtl::move_alloc(this->ptr_alloc(), x.ptr_alloc(), flag);
-            //Nothrow swap
-            this->swap_members(x);
-         }
-         //Else do a one by one move
-         else{
-            this->assign( boost::make_move_iterator(x.begin())
-                        , boost::make_move_iterator(x.end()));
-         }
+         //We know resources can be transferred at comiple time if both allocators are
+         //always equal or the allocator is going to be propagated
+         const bool can_steal_resources_alloc
+            =  allocator_traits_type::propagate_on_container_move_assignment::value
+            || allocator_traits_type::is_always_equal::value;
+         dtl::bool_<can_steal_resources_alloc> flag;
+         this->priv_move_assign(boost::move(x), flag);
       }
       return *this;
    }
@@ -1741,7 +2176,7 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
    void pop_front() BOOST_NOEXCEPT_OR_NOTHROW
    {
       BOOST_ASSERT(!this->empty());
-      if (this->members_.m_start.m_cur != this->members_.m_start.m_last - 1) {
+      if (this->members_.m_start.m_cur != this->members_.m_start.get_last() - 1) {
          allocator_traits_type::destroy
             ( this->alloc()
             , boost::movelib::to_raw_pointer(this->members_.m_start.m_cur)
@@ -1760,7 +2195,7 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
    void pop_back() BOOST_NOEXCEPT_OR_NOTHROW
    {
       BOOST_ASSERT(!this->empty());
-      if (this->members_.m_finish.m_cur != this->members_.m_finish.m_first) {
+      if (this->members_.m_finish.m_cur != this->members_.m_finish.get_first()) {
          --this->members_.m_finish.m_cur;
          allocator_traits_type::destroy
             ( this->alloc()
@@ -1865,9 +2300,9 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
          }
 
          if (this->members_.m_start.m_node != this->members_.m_finish.m_node) {
-            this->priv_destroy_range(this->members_.m_start.m_cur, this->members_.m_start.m_last);
-            this->priv_destroy_range(this->members_.m_finish.m_first, this->members_.m_finish.m_cur);
-            this->priv_deallocate_node(this->members_.m_finish.m_first);
+            this->priv_destroy_range(this->members_.m_start.m_cur, this->members_.m_start.get_last());
+            this->priv_destroy_range(this->members_.m_finish.get_first(), this->members_.m_finish.m_cur);
+            this->priv_deallocate_node(this->members_.m_finish.get_first());
          }
          else
             this->priv_destroy_range(this->members_.m_start.m_cur, this->members_.m_finish.m_cur);
@@ -1928,6 +2363,30 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
    #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
    private:
 
+   void priv_move_assign(BOOST_RV_REF(deque) x, dtl::bool_<true> /*steal_resources*/)
+   {
+      //Destroy objects but retain memory in case x reuses it in the future
+      this->clear();
+      //Move allocator if needed
+      dtl::bool_<allocator_traits_type::propagate_on_container_move_assignment::value> flag;
+      dtl::move_alloc(this->alloc(), x.alloc(), flag);
+      dtl::move_alloc(this->ptr_alloc(), x.ptr_alloc(), flag);
+      //Nothrow swap
+      this->swap_members(x);
+   }
+
+   void priv_move_assign(BOOST_RV_REF(deque) x, dtl::bool_<false> /*steal_resources*/)
+   {
+      //We can't guarantee a compile-time equal allocator or propagation so fallback to runtime
+      //Resources can be transferred if both allocators are equal
+      if (this->alloc() == x.alloc()) {
+         this->priv_move_assign(boost::move(x), dtl::true_());
+      }
+      else {
+         this->assign(boost::make_move_iterator(x.begin()), boost::make_move_iterator(x.end()));
+      }
+   }
+
    inline size_type priv_index_of(const_iterator p) const
    {
       BOOST_ASSERT(this->cbegin() <= p);
@@ -2016,7 +2475,7 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
    inline bool priv_push_back_simple_available() const
    {
       return this->members_.m_map &&
-         (this->members_.m_finish.m_cur != (this->members_.m_finish.m_last - 1));
+         (this->members_.m_finish.m_cur != (this->members_.m_finish.get_last() - 1));
    }
 
    inline T *priv_push_back_simple_pos() const
@@ -2032,7 +2491,7 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
    inline bool priv_push_front_simple_available() const
    {
       return this->members_.m_map &&
-         (this->members_.m_start.m_cur != this->members_.m_start.m_first);
+         (this->members_.m_start.m_cur != this->members_.m_start.get_first());
    }
 
    inline T *priv_push_front_simple_pos() const
@@ -2043,7 +2502,8 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
 
    void priv_destroy_range(iterator p, iterator p2)
    {
-      if(!Base::traits_t::trivial_dctr){
+      (void)p; (void)p2;
+      BOOST_IF_CONSTEXPR(!Base::traits_t::trivial_dctr){
          for(;p != p2; ++p){
             allocator_traits_type::destroy(this->alloc(), boost::movelib::iterator_to_raw_pointer(p));
          }
@@ -2052,7 +2512,8 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
 
    void priv_destroy_range(pointer p, pointer p2)
    {
-      if(!Base::traits_t::trivial_dctr){
+      (void)p; (void)p2;
+      BOOST_IF_CONSTEXPR(!Base::traits_t::trivial_dctr){
          for(;p != p2; ++p){
             allocator_traits_type::destroy(this->alloc(), boost::movelib::iterator_to_raw_pointer(p));
          }
@@ -2060,84 +2521,117 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
    }
 
    template<class InsertProxy>
-   iterator priv_insert_aux_impl(const_iterator p, size_type n, InsertProxy proxy)
+   iterator priv_insert_middle_aux_impl(const_iterator p, const size_type elemsbefore, const size_type length, const size_type n, InsertProxy proxy)
    {
-      iterator pos(p.unconst());
-      const size_type pos_n = size_type(p - this->cbegin());
-      if(!this->members_.m_map){
+      if (!this->members_.m_map) {
          this->priv_initialize_map(0);
-         pos = this->begin();
+         p = this->cbegin();
       }
 
-      const size_type elemsbefore = static_cast<size_type>(pos - this->members_.m_start);
-      const size_type length = this->size();
+      iterator pos(p.unconst());
+      const size_type pos_n = size_type(p - this->cbegin());
+
       if (elemsbefore < length / 2) {
          const iterator new_start = this->priv_reserve_elements_at_front(n);
          const iterator old_start = this->members_.m_start;
-         if(!elemsbefore){
-            proxy.uninitialized_copy_n_and_update(this->alloc(), new_start, n);
-            this->members_.m_start = new_start;
-         }
-         else{
-            pos = this->members_.m_start + difference_type(elemsbefore);
-            if (elemsbefore >= n) {
-               const iterator start_n = this->members_.m_start + difference_type(n);
+         pos = this->members_.m_start + difference_type(elemsbefore);
+         if (elemsbefore >= n) {
+            const iterator start_n = this->members_.m_start + difference_type(n);
+            BOOST_CONTAINER_TRY {
                ::boost::container::uninitialized_move_alloc
                   (this->alloc(), this->members_.m_start, start_n, new_start);
-               this->members_.m_start = new_start;
-               boost::container::move(start_n, pos, old_start);
-               proxy.copy_n_and_update(this->alloc(), pos - difference_type(n), n);
             }
-            else {
-               const size_type mid_count = n - elemsbefore;
-               const iterator mid_start = old_start - difference_type(mid_count);
+            BOOST_CONTAINER_CATCH(...) {
+               this->priv_destroy_nodes(new_start.m_node, this->members_.m_start.m_node);
+               BOOST_CONTAINER_RETHROW
+            }
+            BOOST_CONTAINER_CATCH_END
+            this->members_.m_start = new_start;
+            boost::container::move(start_n, pos, old_start);
+            proxy.copy_n_and_update(this->alloc(), pos - difference_type(n), n);
+         }
+         else {
+            const size_type mid_count = n - elemsbefore;
+            const iterator mid_start = old_start - difference_type(mid_count);
+            BOOST_CONTAINER_TRY {
                proxy.uninitialized_copy_n_and_update(this->alloc(), mid_start, mid_count);
                this->members_.m_start = mid_start;
-               ::boost::container::uninitialized_move_alloc
-                  (this->alloc(), old_start, pos, new_start);
-               this->members_.m_start = new_start;
-               proxy.copy_n_and_update(this->alloc(), old_start, elemsbefore);
+               ::boost::container::uninitialized_move_alloc(this->alloc(), old_start, pos, new_start);
+            }
+            BOOST_CONTAINER_CATCH(...) {
+               this->priv_destroy_nodes(new_start.m_node, this->members_.m_start.m_node);
+               BOOST_CONTAINER_RETHROW
             }
+            BOOST_CONTAINER_CATCH_END
+            this->members_.m_start = new_start;
+            proxy.copy_n_and_update(this->alloc(), old_start, elemsbefore);
          }
       }
       else {
          const iterator new_finish = this->priv_reserve_elements_at_back(n);
          const iterator old_finish = this->members_.m_finish;
          const size_type elemsafter = length - elemsbefore;
-         if(!elemsafter){
-            proxy.uninitialized_copy_n_and_update(this->alloc(), old_finish, n);
+
+         pos = old_finish - difference_type(elemsafter);
+         if (elemsafter >= n) {
+            iterator finish_n = old_finish - difference_type(n);
+            BOOST_CONTAINER_TRY {
+               ::boost::container::uninitialized_move_alloc(this->alloc(), finish_n, old_finish, old_finish);
+            }
+            BOOST_CONTAINER_CATCH(...) {
+               this->priv_destroy_nodes(this->members_.m_finish.m_node + 1, new_finish.m_node + 1);
+               BOOST_CONTAINER_RETHROW
+            }
+            BOOST_CONTAINER_CATCH_END
+
             this->members_.m_finish = new_finish;
+            boost::container::move_backward(pos, finish_n, old_finish);
+            proxy.copy_n_and_update(this->alloc(), pos, n);
          }
-         else{
-            pos = old_finish - difference_type(elemsafter);
-            if (elemsafter >= n) {
-               iterator finish_n = old_finish - difference_type(n);
-               ::boost::container::uninitialized_move_alloc
-                  (this->alloc(), finish_n, old_finish, old_finish);
-               this->members_.m_finish = new_finish;
-               boost::container::move_backward(pos, finish_n, old_finish);
-               proxy.copy_n_and_update(this->alloc(), pos, n);
-            }
-            else {
-               const size_type raw_gap = n - elemsafter;
+         else {
+            const size_type raw_gap = n - elemsafter;
+            BOOST_CONTAINER_TRY{
                ::boost::container::uninitialized_move_alloc
                   (this->alloc(), pos, old_finish, old_finish + difference_type(raw_gap));
                BOOST_CONTAINER_TRY{
                   proxy.copy_n_and_update(this->alloc(), pos, elemsafter);
                   proxy.uninitialized_copy_n_and_update(this->alloc(), old_finish, raw_gap);
                }
-               BOOST_CONTAINER_CATCH(...){
+               BOOST_CONTAINER_CATCH(...) {
                   this->priv_destroy_range(old_finish, old_finish + difference_type(elemsafter));
                   BOOST_CONTAINER_RETHROW
                }
                BOOST_CONTAINER_CATCH_END
-               this->members_.m_finish = new_finish;
             }
+            BOOST_CONTAINER_CATCH(...) {
+               this->priv_destroy_nodes(this->members_.m_finish.m_node + 1, new_finish.m_node + 1);
+               BOOST_CONTAINER_RETHROW
+            }
+            BOOST_CONTAINER_CATCH_END
+            this->members_.m_finish = new_finish;
          }
       }
       return this->begin() + difference_type(pos_n);
    }
 
+   template<class InsertProxy>
+   iterator priv_insert_aux_impl(const_iterator p, size_type n, InsertProxy proxy)
+   {
+      iterator pos(p.unconst());
+      const size_type elemsbefore = static_cast<size_type>(pos - this->members_.m_start);
+      const size_type length = this->size();
+
+      if (!elemsbefore) {
+         return this->priv_insert_front_aux_impl(n, proxy);
+      }
+      else if (elemsbefore == length) {
+         return this->priv_insert_back_aux_impl(n, proxy);
+      }
+      else {
+         return this->priv_insert_middle_aux_impl(p, elemsbefore, length, n, proxy);
+      }
+   }
+
    template <class InsertProxy>
    iterator priv_insert_back_aux_impl(size_type n, InsertProxy proxy)
    {
@@ -2146,8 +2640,14 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
       }
 
       iterator new_finish = this->priv_reserve_elements_at_back(n);
-      iterator old_finish = this->members_.m_finish;
-      proxy.uninitialized_copy_n_and_update(this->alloc(), old_finish, n);
+      BOOST_CONTAINER_TRY{
+         proxy.uninitialized_copy_n_and_update(this->alloc(), this->members_.m_finish, n);
+      }
+      BOOST_CONTAINER_CATCH(...) {
+         this->priv_destroy_nodes(this->members_.m_finish.m_node + 1, new_finish.m_node + 1);
+         BOOST_CONTAINER_RETHROW
+      }
+      BOOST_CONTAINER_CATCH_END
       this->members_.m_finish = new_finish;
       return iterator(this->members_.m_finish - difference_type(n));
    }
@@ -2160,7 +2660,15 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
       }
 
       iterator new_start = this->priv_reserve_elements_at_front(n);
-      proxy.uninitialized_copy_n_and_update(this->alloc(), new_start, n);
+      BOOST_CONTAINER_TRY{
+         proxy.uninitialized_copy_n_and_update(this->alloc(), new_start, n);
+      }
+      BOOST_CONTAINER_CATCH(...) {
+         this->priv_destroy_nodes(new_start.m_node, this->members_.m_start.m_node);
+         BOOST_CONTAINER_RETHROW
+      }
+      BOOST_CONTAINER_CATCH_END
+
       this->members_.m_start = new_start;
       return new_start;
    }
@@ -2181,7 +2689,7 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
                (this->alloc(), *cur, *cur + get_block_ssize(), value);
          }
          boost::container::uninitialized_fill_alloc
-            (this->alloc(), this->members_.m_finish.m_first, this->members_.m_finish.m_cur, value);
+            (this->alloc(), this->members_.m_finish.get_first(), this->members_.m_finish.m_cur, value);
       }
       BOOST_CONTAINER_CATCH(...){
          this->priv_destroy_range(this->members_.m_start, iterator(*cur, cur, get_block_size()));
@@ -2220,7 +2728,7 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
             ::boost::container::uninitialized_copy_alloc(this->alloc(), first, mid, *cur_node);
             first = mid;
          }
-         ::boost::container::uninitialized_copy_alloc(this->alloc(), first, last, this->members_.m_finish.m_first);
+         ::boost::container::uninitialized_copy_alloc(this->alloc(), first, last, this->members_.m_finish.get_first());
       }
       BOOST_CONTAINER_CATCH(...){
          this->priv_destroy_range(this->members_.m_start, iterator(*cur_node, cur_node, get_block_size()));
@@ -2229,21 +2737,21 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
       BOOST_CONTAINER_CATCH_END
    }
 
-   // Called only if this->members_.m_finish.m_cur == this->members_.m_finish.m_first.
+   // Called only if this->members_.m_finish.m_cur == this->members_.m_finish.get_first().
    void priv_pop_back_aux() BOOST_NOEXCEPT_OR_NOTHROW
    {
-      this->priv_deallocate_node(this->members_.m_finish.m_first);
+      this->priv_deallocate_node(this->members_.m_finish.get_first());
       this->members_.m_finish.priv_set_node(this->members_.m_finish.m_node - 1, get_block_size());
-      this->members_.m_finish.m_cur = this->members_.m_finish.m_last - 1;
+      this->members_.m_finish.m_cur = this->members_.m_finish.get_last() - 1;
       allocator_traits_type::destroy
          ( this->alloc()
          , boost::movelib::to_raw_pointer(this->members_.m_finish.m_cur)
          );
    }
 
-   // Called only if this->members_.m_start.m_cur == this->members_.m_start.m_last - 1.  Note that
+   // Called only if this->members_.m_start.m_cur == this->members_.m_start.get_last() - 1.  Note that
    // if the deque has at least one element (a precondition for this member
-   // function), and if this->members_.m_start.m_cur == this->members_.m_start.m_last, then the deque
+   // function), and if this->members_.m_start.m_cur == this->members_.m_start.get_last(), then the deque
    // must have at least two nodes.
    void priv_pop_front_aux() BOOST_NOEXCEPT_OR_NOTHROW
    {
@@ -2251,14 +2759,14 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
          ( this->alloc()
          , boost::movelib::to_raw_pointer(this->members_.m_start.m_cur)
          );
-      this->priv_deallocate_node(this->members_.m_start.m_first);
+      this->priv_deallocate_node(this->members_.m_start.get_first());
       this->members_.m_start.priv_set_node(this->members_.m_start.m_node + 1, get_block_size());
-      this->members_.m_start.m_cur = this->members_.m_start.m_first;
+      this->members_.m_start.m_cur = this->members_.m_start.get_first();
    }
 
    iterator priv_reserve_elements_at_front(size_type n)
    {
-      size_type vacancies = size_type(this->members_.m_start.m_cur - this->members_.m_start.m_first);
+      size_type vacancies = size_type(this->members_.m_start.m_cur - this->members_.m_start.get_first());
       if (n > vacancies){
          size_type new_elems = n-vacancies;
          size_type new_nodes = (new_elems + get_block_size() - 1u) / get_block_size();
@@ -2283,7 +2791,7 @@ class deque : protected deque_base<typename real_allocator<T, Allocator>::type,
 
    iterator priv_reserve_elements_at_back(size_type n)
    {
-      size_type vacancies = size_type(this->members_.m_finish.m_last - this->members_.m_finish.m_cur - 1);
+      size_type vacancies = size_type(this->members_.m_finish.get_last() - this->members_.m_finish.m_cur - 1);
       if (n > vacancies){
          size_type new_elems = size_type(n - vacancies);
          size_type new_nodes = size_type(new_elems + get_block_size() - 1u)/get_block_size();
@@ -2348,7 +2856,8 @@ template <typename InputIterator, typename Allocator>
 deque(InputIterator, InputIterator, Allocator const&) -> deque<typename iterator_traits<InputIterator>::value_type, Allocator>;
 #endif
 
-}}
+}  //namespace container
+}  //namespace boost
 
 #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
 
@@ -2361,7 +2870,7 @@ struct has_trivial_destructor_after_move<boost::container::deque<T, Allocator, O
 {
    typedef typename boost::container::deque<T, Allocator, Options>::allocator_type allocator_type;
    typedef typename ::boost::container::allocator_traits<allocator_type>::pointer pointer;
-   static const bool value = ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
+   BOOST_STATIC_CONSTEXPR bool value = ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
                              ::boost::has_trivial_destructor_after_move<pointer>::value;
 };
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/adaptive_node_pool.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/adaptive_node_pool.hpp
index 9dd89b1331..816b95d1ce 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/adaptive_node_pool.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/adaptive_node_pool.hpp
@@ -76,7 +76,7 @@ class private_adaptive_node_pool
    private_adaptive_node_pool &operator=(const private_adaptive_node_pool &);
 
    public:
-   static const std::size_t nodes_per_block = NodesPerBlock;
+   BOOST_STATIC_CONSTEXPR std::size_t nodes_per_block = NodesPerBlock;
 
    //!Constructor. Never throws
    private_adaptive_node_pool()
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/adaptive_node_pool_impl.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/adaptive_node_pool_impl.hpp
index e3400977de..119b5b6153 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/adaptive_node_pool_impl.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/adaptive_node_pool_impl.hpp
@@ -49,10 +49,10 @@ namespace container {
 
 namespace adaptive_pool_flag {
 
-static const unsigned int none            = 0u;
-static const unsigned int align_only      = 1u << 0u;
-static const unsigned int size_ordered    = 1u << 1u;
-static const unsigned int address_ordered = 1u << 2u;
+BOOST_CONTAINER_CONSTANT_VAR unsigned int none            = 0u;
+BOOST_CONTAINER_CONSTANT_VAR unsigned int align_only      = 1u << 0u;
+BOOST_CONTAINER_CONSTANT_VAR unsigned int size_ordered    = 1u << 1u;
+BOOST_CONTAINER_CONSTANT_VAR unsigned int address_ordered = 1u << 2u;
 
 }  //namespace adaptive_pool_flag{
 
@@ -213,11 +213,11 @@ template<class MultiallocationChain, class VoidPointer, class SizeType, unsigned
 struct adaptive_pool_types
 {
    typedef VoidPointer void_pointer;
-   static const unsigned ordered = (Flags & (adaptive_pool_flag::size_ordered | adaptive_pool_flag::address_ordered));
+   BOOST_STATIC_CONSTEXPR unsigned ordered = (Flags & (adaptive_pool_flag::size_ordered | adaptive_pool_flag::address_ordered));
    typedef block_container_traits<VoidPointer, SizeType, ordered> block_container_traits_t;
    typedef typename block_container_traits_t::hook_t hook_t;
    typedef hdr_offset_holder_t<SizeType> hdr_offset_holder;
-   static const unsigned int order_flags = Flags & (adaptive_pool_flag::size_ordered | adaptive_pool_flag::address_ordered);
+   BOOST_STATIC_CONSTEXPR unsigned int order_flags = Flags & (adaptive_pool_flag::size_ordered | adaptive_pool_flag::address_ordered);
    typedef MultiallocationChain free_nodes_t;
 
    struct block_info_t
@@ -253,11 +253,11 @@ template< std::size_t alignment
         , std::size_t overhead_percent>
 struct candidate_power_of_2_ct_helper
 {
-   static const std::size_t hdr_subblock_elements_alone = (alignment - hdr_size - payload_per_allocation)/real_node_size;
-   static const std::size_t hdr_subblock_elements_first = (alignment - hdr_size - payload_per_allocation)/real_node_size;
-   static const std::size_t elements_per_b_subblock_mid = (alignment - hdr_offset_size)/real_node_size;
-   static const std::size_t elements_per_b_subblock_end = (alignment - hdr_offset_size - payload_per_allocation)/real_node_size;
-   static const std::size_t num_b_subblock =
+   BOOST_STATIC_CONSTEXPR std::size_t hdr_subblock_elements_alone = (alignment - hdr_size - payload_per_allocation)/real_node_size;
+   BOOST_STATIC_CONSTEXPR std::size_t hdr_subblock_elements_first = (alignment - hdr_size - payload_per_allocation)/real_node_size;
+   BOOST_STATIC_CONSTEXPR std::size_t elements_per_b_subblock_mid = (alignment - hdr_offset_size)/real_node_size;
+   BOOST_STATIC_CONSTEXPR std::size_t elements_per_b_subblock_end = (alignment - hdr_offset_size - payload_per_allocation)/real_node_size;
+   BOOST_STATIC_CONSTEXPR std::size_t num_b_subblock =
       hdr_subblock_elements_alone >= min_elements_per_block
          ? 0
          : (   ((hdr_subblock_elements_first + elements_per_b_subblock_end) >= min_elements_per_block)
@@ -266,18 +266,18 @@ struct candidate_power_of_2_ct_helper
             )
          ;
 
-   static const std::size_t num_b_subblock_mid = (num_b_subblock > 1) ? (num_b_subblock - 1) : 0;
+   BOOST_STATIC_CONSTEXPR std::size_t num_b_subblock_mid = (num_b_subblock > 1) ? (num_b_subblock - 1) : 0;
 
-   static const std::size_t total_nodes = (num_b_subblock == 0)
+   BOOST_STATIC_CONSTEXPR std::size_t total_nodes = (num_b_subblock == 0)
                                          ? hdr_subblock_elements_alone
                                          : ( (num_b_subblock == 1)
                                            ? (hdr_subblock_elements_first + elements_per_b_subblock_end)
                                            : (hdr_subblock_elements_first + num_b_subblock_mid*elements_per_b_subblock_mid + elements_per_b_subblock_end)
                                            )
                                          ;
-   static const std::size_t total_data = total_nodes*real_node_size;
-   static const std::size_t total_size = alignment*(num_b_subblock+1);
-   static const bool overhead_satisfied = (total_size - total_data)*100/total_size < overhead_percent;
+   BOOST_STATIC_CONSTEXPR std::size_t total_data = total_nodes*real_node_size;
+   BOOST_STATIC_CONSTEXPR std::size_t total_size = alignment*(num_b_subblock+1);
+   BOOST_STATIC_CONSTEXPR bool overhead_satisfied = (total_size - total_data)*100/total_size < overhead_percent;
 };
 
 template< std::size_t initial_alignment
@@ -299,7 +299,7 @@ struct candidate_power_of_2_ct
         , hdr_offset_size
         , overhead_percent> helper_t;
 
-   static const std::size_t candidate_power_of_2 = initial_alignment << std::size_t(!helper_t::overhead_satisfied);
+   BOOST_STATIC_CONSTEXPR std::size_t candidate_power_of_2 = initial_alignment << std::size_t(!helper_t::overhead_satisfied);
 
    typedef typename candidate_power_of_2_ct
       < candidate_power_of_2
@@ -312,9 +312,9 @@ struct candidate_power_of_2_ct
       , !helper_t::overhead_satisfied
       >::type type;
 
-   static const std::size_t alignment     = type::alignment;
-   static const std::size_t num_subblocks = type::num_subblocks;
-   static const std::size_t real_num_node = type::real_num_node;
+   BOOST_STATIC_CONSTEXPR std::size_t alignment     = type::alignment;
+   BOOST_STATIC_CONSTEXPR std::size_t num_subblocks = type::num_subblocks;
+   BOOST_STATIC_CONSTEXPR std::size_t real_num_node = type::real_num_node;
 };
 
 template< std::size_t initial_alignment
@@ -354,9 +354,9 @@ struct candidate_power_of_2_ct
         , hdr_offset_size
         , overhead_percent> helper_t;
 
-   static const std::size_t alignment = initial_alignment;
-   static const std::size_t num_subblocks = helper_t::num_b_subblock+1;
-   static const std::size_t real_num_node = helper_t::total_nodes;
+   BOOST_STATIC_CONSTEXPR std::size_t alignment = initial_alignment;
+   BOOST_STATIC_CONSTEXPR std::size_t num_subblocks = helper_t::num_b_subblock+1;
+   BOOST_STATIC_CONSTEXPR std::size_t real_num_node = helper_t::total_nodes;
 };
 
 /////////////////////////////////////////////
@@ -429,13 +429,13 @@ class private_adaptive_node_pool_impl_common
    typedef typename SegmentManagerBase::size_type                    size_type;
    //Flags
    //align_only
-   static const bool AlignOnly      = (Flags & adaptive_pool_flag::align_only) != 0;
+   BOOST_STATIC_CONSTEXPR bool AlignOnly      = (Flags & adaptive_pool_flag::align_only) != 0;
    typedef bool_<AlignOnly>            IsAlignOnly;
    typedef true_                       AlignOnlyTrue;
    typedef false_                      AlignOnlyFalse;
 
    typedef typename SegmentManagerBase::void_pointer void_pointer;
-   static const typename SegmentManagerBase::
+   BOOST_STATIC_CONSTEXPR typename SegmentManagerBase::
       size_type PayloadPerAllocation = SegmentManagerBase::PayloadPerAllocation;
 
    typedef typename boost::intrusive::pointer_traits
@@ -453,9 +453,9 @@ class private_adaptive_node_pool_impl_common
    typedef typename adaptive_pool_types_t::hdr_offset_holder         hdr_offset_holder;
    typedef private_adaptive_node_pool_impl_common                    this_type;
 
-   static const size_type MaxAlign = alignment_of<void_pointer>::value;
-   static const size_type HdrSize  = ((sizeof(block_info_t)-1)/MaxAlign+1)*MaxAlign;
-   static const size_type HdrOffsetSize = ((sizeof(hdr_offset_holder)-1)/MaxAlign+1)*MaxAlign;
+   BOOST_STATIC_CONSTEXPR size_type MaxAlign = alignment_of<void_pointer>::value;
+   BOOST_STATIC_CONSTEXPR size_type HdrSize  = ((sizeof(block_info_t)-1)/MaxAlign+1)*MaxAlign;
+   BOOST_STATIC_CONSTEXPR size_type HdrOffsetSize = ((sizeof(hdr_offset_holder)-1)/MaxAlign+1)*MaxAlign;
 
    segment_mngr_base_ptr_t             mp_segment_mngr_base;   //Segment manager
    block_container_t                   m_block_container;      //Intrusive block list
@@ -981,9 +981,9 @@ template< class SizeType
         , bool AlignOnly>
 struct calculate_alignment_ct
 {
-   static const std::size_t alignment     = upper_power_of_2_ct<SizeType, HdrSize + RealNodeSize*NodesPerBlock>::value;
-   static const std::size_t num_subblocks = 0;
-   static const std::size_t real_num_node = (alignment - PayloadPerAllocation - HdrSize)/RealNodeSize;
+   BOOST_STATIC_CONSTEXPR std::size_t alignment     = upper_power_of_2_ct<SizeType, HdrSize + RealNodeSize*NodesPerBlock>::value;
+   BOOST_STATIC_CONSTEXPR std::size_t num_subblocks = 0;
+   BOOST_STATIC_CONSTEXPR std::size_t real_num_node = (alignment - PayloadPerAllocation - HdrSize)/RealNodeSize;
 };
 
 template< class SizeType
@@ -1013,9 +1013,9 @@ struct calculate_alignment_ct
       , OverheadPercent
       >::type type;
 
-   static const std::size_t alignment     = type::alignment;
-   static const std::size_t num_subblocks = type::num_subblocks;
-   static const std::size_t real_num_node = type::real_num_node;
+   BOOST_STATIC_CONSTEXPR std::size_t alignment     = type::alignment;
+   BOOST_STATIC_CONSTEXPR std::size_t num_subblocks = type::num_subblocks;
+   BOOST_STATIC_CONSTEXPR std::size_t real_num_node = type::real_num_node;
 };
 
 
@@ -1046,17 +1046,17 @@ class private_adaptive_node_pool_impl_ct
    typedef typename base_t::multiallocation_chain     multiallocation_chain;
    typedef typename base_t::segment_manager_base_type segment_manager_base_type;
 
-   static const typename base_t::size_type PayloadPerAllocation = base_t::PayloadPerAllocation;
+   BOOST_STATIC_CONSTEXPR typename base_t::size_type PayloadPerAllocation = base_t::PayloadPerAllocation;
 
    //align_only
-   static const bool AlignOnly      = base_t::AlignOnly;
+   BOOST_STATIC_CONSTEXPR bool AlignOnly      = base_t::AlignOnly;
 
    private:
-   static const size_type MaxAlign = base_t::MaxAlign;
-   static const size_type HdrSize  = base_t::HdrSize;
-   static const size_type HdrOffsetSize = base_t::HdrOffsetSize;
+   BOOST_STATIC_CONSTEXPR size_type MaxAlign = base_t::MaxAlign;
+   BOOST_STATIC_CONSTEXPR size_type HdrSize  = base_t::HdrSize;
+   BOOST_STATIC_CONSTEXPR size_type HdrOffsetSize = base_t::HdrOffsetSize;
 
-   static const size_type RealNodeSize = lcm_ct<NodeSize, alignment_of<void_pointer>::value>::value;
+   BOOST_STATIC_CONSTEXPR size_type RealNodeSize = lcm_ct<NodeSize, alignment_of<void_pointer>::value>::value;
 
    typedef calculate_alignment_ct
       < size_type, HdrSize, PayloadPerAllocation
@@ -1065,9 +1065,9 @@ class private_adaptive_node_pool_impl_ct
    //Round the size to a power of two value.
    //This is the total memory size (including payload) that we want to
    //allocate from the general-purpose allocator
-   static const size_type NumSubBlocks       = data_t::num_subblocks;
-   static const size_type RealNumNode        = data_t::real_num_node;
-   static const size_type RealBlockAlignment = data_t::alignment;
+   BOOST_STATIC_CONSTEXPR size_type NumSubBlocks       = data_t::num_subblocks;
+   BOOST_STATIC_CONSTEXPR size_type RealNumNode        = data_t::real_num_node;
+   BOOST_STATIC_CONSTEXPR size_type RealBlockAlignment = data_t::alignment;
 
    public:
 
@@ -1165,14 +1165,14 @@ class private_adaptive_node_pool_impl_rt
    typedef typename impl_t::size_type              size_type;
    typedef typename impl_t::multiallocation_chain  multiallocation_chain;
 
-   static const typename impl_t::size_type PayloadPerAllocation = impl_t::PayloadPerAllocation;
+   BOOST_STATIC_CONSTEXPR typename impl_t::size_type PayloadPerAllocation = impl_t::PayloadPerAllocation;
 
    //Flags
    //align_only
-   static const bool AlignOnly      = impl_t::AlignOnly;
+   BOOST_STATIC_CONSTEXPR bool AlignOnly      = impl_t::AlignOnly;
 
-   static const size_type HdrSize  = impl_t::HdrSize;
-   static const size_type HdrOffsetSize = impl_t::HdrOffsetSize;
+   BOOST_STATIC_CONSTEXPR size_type HdrSize  = impl_t::HdrSize;
+   BOOST_STATIC_CONSTEXPR size_type HdrOffsetSize = impl_t::HdrOffsetSize;
 
    public:
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/advanced_insert_int.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/advanced_insert_int.hpp
index bc6801adb4..e16082a741 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/advanced_insert_int.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/advanced_insert_int.hpp
@@ -39,6 +39,7 @@
 
 #include <boost/move/utility_core.hpp>
 #include <boost/move/detail/force_ptr.hpp>
+#include <boost/move/detail/launder.hpp>
 // other
 #include <boost/assert.hpp>
 
@@ -138,8 +139,8 @@ struct insert_value_initialized_n_proxy
       while (n){
          --n;
          storage_t v;
-         alloc_traits::construct(a, move_detail::force_ptr<value_type *>(&v));
-         value_type *vp = move_detail::force_ptr<value_type *>(&v);
+         alloc_traits::construct(a, (value_type*)&v);
+         value_type *vp = move_detail::launder_cast<value_type *>(&v);
          value_destructor<Allocator> on_exit(a, *vp); (void)on_exit;
          *p = ::boost::move(*vp);
          ++p;
@@ -165,8 +166,8 @@ struct insert_default_initialized_n_proxy
          while (n){
             --n;
             typename dtl::aligned_storage<sizeof(value_type), dtl::alignment_of<value_type>::value>::type v;
-            alloc_traits::construct(a, move_detail::force_ptr<value_type *>(&v), default_init);
-            value_type *vp = move_detail::force_ptr<value_type *>(&v);
+            alloc_traits::construct(a, (value_type*)&v, default_init);
+            value_type *vp = move_detail::launder_cast<value_type *>(&v);
             value_destructor<Allocator> on_exit(a, *vp); (void)on_exit;
             *p = ::boost::move(*vp);
             ++p;
@@ -181,7 +182,7 @@ struct insert_copy_proxy
    typedef boost::container::allocator_traits<Allocator> alloc_traits;
    typedef typename alloc_traits::value_type value_type;
 
-   static const bool single_value = true;
+   BOOST_STATIC_CONSTEXPR bool single_value = true;
 
    inline explicit insert_copy_proxy(const value_type &v)
       :  v_(v)
@@ -211,7 +212,7 @@ struct insert_move_proxy
    typedef boost::container::allocator_traits<Allocator> alloc_traits;
    typedef typename alloc_traits::value_type value_type;
 
-   static const bool single_value = true;
+   BOOST_STATIC_CONSTEXPR bool single_value = true;
 
    inline explicit insert_move_proxy(value_type &v)
       :  v_(v)
@@ -264,7 +265,7 @@ struct insert_nonmovable_emplace_proxy
    typedef typename alloc_traits::value_type       value_type;
    typedef typename build_number_seq<sizeof...(Args)>::type index_tuple_t;
 
-   static const bool single_value = true;
+   BOOST_STATIC_CONSTEXPR bool single_value = true;
 
    inline explicit insert_nonmovable_emplace_proxy(BOOST_FWD_REF(Args)... args)
       : args_(args...)
@@ -295,7 +296,7 @@ struct insert_emplace_proxy
    typedef typename base_t::value_type             value_type;
    typedef typename base_t::index_tuple_t          index_tuple_t;
 
-   static const bool single_value = true;
+   BOOST_STATIC_CONSTEXPR bool single_value = true;
 
    inline explicit insert_emplace_proxy(BOOST_FWD_REF(Args)... args)
       : base_t(::boost::forward<Args>(args)...)
@@ -312,8 +313,8 @@ struct insert_emplace_proxy
    {
       BOOST_ASSERT(n ==1); (void)n;
       typename dtl::aligned_storage<sizeof(value_type), dtl::alignment_of<value_type>::value>::type v;
-      alloc_traits::construct(a, move_detail::force_ptr<value_type *>(&v), ::boost::forward<Args>(get<IdxPack>(this->args_))...);
-      value_type *vp = move_detail::force_ptr<value_type *>(&v);
+      alloc_traits::construct(a, (value_type*)&v, ::boost::forward<Args>(get<IdxPack>(this->args_))...);
+      value_type *vp = move_detail::launder_cast<value_type *>(&v);
       BOOST_CONTAINER_TRY{
          *p = ::boost::move(*vp);
       }
@@ -331,7 +332,7 @@ template<class Allocator>
 struct insert_emplace_proxy<Allocator, typename boost::container::allocator_traits<Allocator>::value_type>
    : public insert_move_proxy<Allocator>
 {
-   static const bool single_value = true;
+   BOOST_STATIC_CONSTEXPR bool single_value = true;
 
    inline explicit insert_emplace_proxy(typename boost::container::allocator_traits<Allocator>::value_type &&v)
    : insert_move_proxy<Allocator>(v)
@@ -348,7 +349,7 @@ struct insert_emplace_proxy<Allocator
    : public insert_copy_proxy<Allocator>
 {
 
-   static const bool single_value = true;
+   BOOST_STATIC_CONSTEXPR bool single_value = true;
 
    inline explicit insert_emplace_proxy(const typename boost::container::allocator_traits<Allocator>::value_type &v)
    : insert_copy_proxy<Allocator>(v)
@@ -359,7 +360,7 @@ template<class Allocator>
 struct insert_emplace_proxy<Allocator, typename boost::container::allocator_traits<Allocator>::value_type &>
    : public insert_copy_proxy<Allocator>
 {
-   static const bool single_value = true;
+   BOOST_STATIC_CONSTEXPR bool single_value = true;
 
    inline explicit insert_emplace_proxy(const typename boost::container::allocator_traits<Allocator>::value_type &v)
    : insert_copy_proxy<Allocator>(v)
@@ -372,7 +373,7 @@ struct insert_emplace_proxy<Allocator
    >
    : public insert_copy_proxy<Allocator>
 {
-   static const bool single_value = true;
+   BOOST_STATIC_CONSTEXPR bool single_value = true;
 
    inline explicit insert_emplace_proxy(const typename boost::container::allocator_traits<Allocator>::value_type &v)
    : insert_copy_proxy<Allocator>(v)
@@ -396,7 +397,7 @@ struct insert_nonmovable_emplace_proxy##N\
    typedef boost::container::allocator_traits<Allocator> alloc_traits;\
    typedef typename alloc_traits::value_type value_type;\
    \
-   static const bool single_value = true;\
+   BOOST_STATIC_CONSTEXPR bool single_value = true;\
    \
    inline explicit insert_nonmovable_emplace_proxy##N(BOOST_MOVE_UREF##N)\
       BOOST_MOVE_COLON##N BOOST_MOVE_FWD_INIT##N {}\
@@ -425,7 +426,7 @@ struct insert_emplace_proxy_arg##N\
    typedef typename base_t::value_type value_type;\
    typedef boost::container::allocator_traits<Allocator> alloc_traits;\
    \
-   static const bool single_value = true;\
+   BOOST_STATIC_CONSTEXPR bool single_value = true;\
    \
    inline explicit insert_emplace_proxy_arg##N(BOOST_MOVE_UREF##N)\
       : base_t(BOOST_MOVE_FWD##N){}\
@@ -435,8 +436,8 @@ struct insert_emplace_proxy_arg##N\
    {\
       BOOST_ASSERT(n == 1); (void)n;\
       typename dtl::aligned_storage<sizeof(value_type), dtl::alignment_of<value_type>::value>::type v;\
-      alloc_traits::construct(a, move_detail::force_ptr<value_type *>(&v) BOOST_MOVE_I##N BOOST_MOVE_MFWD##N);\
-      value_type *vp = move_detail::force_ptr<value_type *>(&v);\
+      alloc_traits::construct(a, (value_type*)&v BOOST_MOVE_I##N BOOST_MOVE_MFWD##N);\
+      value_type *vp = move_detail::launder_cast<value_type *>(&v);\
       BOOST_CONTAINER_TRY{\
          *p = ::boost::move(*vp);\
       }\
@@ -459,7 +460,7 @@ template<class Allocator>
 struct insert_emplace_proxy_arg1<Allocator, ::boost::rv<typename boost::container::allocator_traits<Allocator>::value_type> >
    : public insert_move_proxy<Allocator>
 {
-   static const bool single_value = true;
+   BOOST_STATIC_CONSTEXPR bool single_value = true;
 
    inline explicit insert_emplace_proxy_arg1(typename boost::container::allocator_traits<Allocator>::value_type &v)
    : insert_move_proxy<Allocator>(v)
@@ -470,7 +471,7 @@ template<class Allocator>
 struct insert_emplace_proxy_arg1<Allocator, typename boost::container::allocator_traits<Allocator>::value_type>
    : public insert_copy_proxy<Allocator>
 {
-   static const bool single_value = true;
+   BOOST_STATIC_CONSTEXPR bool single_value = true;
 
    inline explicit insert_emplace_proxy_arg1(const typename boost::container::allocator_traits<Allocator>::value_type &v)
    : insert_copy_proxy<Allocator>(v)
@@ -484,7 +485,7 @@ template<class Allocator>
 struct insert_emplace_proxy_arg1<Allocator, typename boost::container::allocator_traits<Allocator>::value_type>
    : public insert_move_proxy<Allocator>
 {
-   static const bool single_value = true;
+   BOOST_STATIC_CONSTEXPR bool single_value = true;
 
    inline explicit insert_emplace_proxy_arg1(typename boost::container::allocator_traits<Allocator>::value_type &&v)
    : insert_move_proxy<Allocator>(v)
@@ -500,7 +501,7 @@ struct insert_emplace_proxy_arg1<Allocator
    >
    : public insert_copy_proxy<Allocator>
 {
-   static const bool single_value = true;
+   BOOST_STATIC_CONSTEXPR bool single_value = true;
 
    inline explicit insert_emplace_proxy_arg1(const typename boost::container::allocator_traits<Allocator>::value_type &v)
    : insert_copy_proxy<Allocator>(v)
@@ -511,7 +512,7 @@ template<class Allocator>
 struct insert_emplace_proxy_arg1<Allocator, typename boost::container::allocator_traits<Allocator>::value_type &>
    : public insert_copy_proxy<Allocator>
 {
-   static const bool single_value = true;
+   BOOST_STATIC_CONSTEXPR bool single_value = true;
 
    inline explicit insert_emplace_proxy_arg1(const typename boost::container::allocator_traits<Allocator>::value_type &v)
    : insert_copy_proxy<Allocator>(v)
@@ -524,7 +525,7 @@ struct insert_emplace_proxy_arg1<Allocator
    >
    : public insert_copy_proxy<Allocator>
 {
-   static const bool single_value = true;
+  BOOST_STATIC_CONSTEXPR bool single_value = true;
 
    inline explicit insert_emplace_proxy_arg1(const typename boost::container::allocator_traits<Allocator>::value_type &v)
    : insert_copy_proxy<Allocator>(v)
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/allocation_type.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/allocation_type.hpp
index 1e8aa67310..5f0d4b62b6 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/allocation_type.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/allocation_type.hpp
@@ -42,13 +42,13 @@ enum allocation_type_v
 
 typedef unsigned int allocation_type;
 #endif   //#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
-static const allocation_type allocate_new       = (allocation_type)allocate_new_v;
-static const allocation_type expand_fwd         = (allocation_type)expand_fwd_v;
-static const allocation_type expand_bwd         = (allocation_type)expand_bwd_v;
-static const allocation_type shrink_in_place    = (allocation_type)shrink_in_place_v;
-static const allocation_type try_shrink_in_place= (allocation_type)try_shrink_in_place_v;
-static const allocation_type nothrow_allocation = (allocation_type)nothrow_allocation_v;
-static const allocation_type zero_memory        = (allocation_type)zero_memory_v;
+BOOST_CONTAINER_CONSTANT_VAR allocation_type allocate_new       = (allocation_type)allocate_new_v;
+BOOST_CONTAINER_CONSTANT_VAR allocation_type expand_fwd         = (allocation_type)expand_fwd_v;
+BOOST_CONTAINER_CONSTANT_VAR allocation_type expand_bwd         = (allocation_type)expand_bwd_v;
+BOOST_CONTAINER_CONSTANT_VAR allocation_type shrink_in_place    = (allocation_type)shrink_in_place_v;
+BOOST_CONTAINER_CONSTANT_VAR allocation_type try_shrink_in_place= (allocation_type)try_shrink_in_place_v;
+BOOST_CONTAINER_CONSTANT_VAR allocation_type nothrow_allocation = (allocation_type)nothrow_allocation_v;
+BOOST_CONTAINER_CONSTANT_VAR allocation_type zero_memory        = (allocation_type)zero_memory_v;
 
 }  //namespace container {
 }  //namespace boost {
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/block_list.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/block_list.hpp
index 0ed0e2279a..4852326788 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/block_list.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/block_list.hpp
@@ -74,11 +74,11 @@ class block_list_base
 {
    list_node m_list;
 
-   static const std::size_t MaxAlignMinus1 = memory_resource::max_align-1u;
+   BOOST_STATIC_CONSTEXPR std::size_t MaxAlignMinus1 = memory_resource::max_align-1u;
 
    public:
 
-   static const std::size_t header_size = std::size_t(sizeof(DerivedFromBlockListHeader) + MaxAlignMinus1) & std::size_t(~MaxAlignMinus1);
+   BOOST_STATIC_CONSTEXPR std::size_t header_size = std::size_t(sizeof(DerivedFromBlockListHeader) + MaxAlignMinus1) & std::size_t(~MaxAlignMinus1);
 
    explicit block_list_base()
    {  list_algo::init_header(&m_list);  }
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/block_slist.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/block_slist.hpp
index 890e72588e..b265ba44c5 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/block_slist.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/block_slist.hpp
@@ -68,11 +68,11 @@ class block_slist_base
 {
    slist_node m_slist;
 
-   static const std::size_t MaxAlignMinus1 = memory_resource::max_align-1u;
+   BOOST_STATIC_CONSTEXPR std::size_t MaxAlignMinus1 = memory_resource::max_align-1u;
 
    public:
 
-   static const std::size_t header_size = std::size_t(sizeof(DerivedFromBlockSlistHeader) + MaxAlignMinus1) & std::size_t(~MaxAlignMinus1);
+   BOOST_STATIC_CONSTEXPR std::size_t header_size = std::size_t(sizeof(DerivedFromBlockSlistHeader) + MaxAlignMinus1) & std::size_t(~MaxAlignMinus1);
 
    explicit block_slist_base()
    {  slist_algo::init_header(&m_slist);  }
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/construct_in_place.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/construct_in_place.hpp
index d824d814af..bfdf05c2e1 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/construct_in_place.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/construct_in_place.hpp
@@ -24,6 +24,7 @@
 #include <boost/container/allocator_traits.hpp>
 #include <boost/container/detail/iterators.hpp>
 #include <boost/container/detail/value_init.hpp>
+#include <boost/container/detail/is_pair.hpp>
 
 namespace boost {
 namespace container {
@@ -62,9 +63,42 @@ BOOST_CONTAINER_FORCEINLINE void construct_in_place(Allocator &a, T *dest, empla
 
 //Assignment
 
+template<class T, class U>
+BOOST_CONTAINER_FORCEINLINE
+   typename dtl::disable_if_c
+      <  dtl::is_pair<typename dtl::remove_reference<T>::type>::value
+      && dtl::is_pair<typename dtl::remove_reference<U>::type>::value
+      , void>::type
+assign_in_place_ref(T &t, BOOST_FWD_REF(U) u)
+{  t = ::boost::forward<U>(u);  }
+
+template<class T, class U>
+BOOST_CONTAINER_FORCEINLINE
+   typename dtl::enable_if_c
+      <  dtl::is_pair<typename dtl::remove_reference<T>::type>::value
+      && dtl::is_pair<typename dtl::remove_reference<U>::type>::value
+      , void>::type
+assign_in_place_ref(T &t, const U &u)
+{
+   assign_in_place_ref(t.first, u.first);
+   assign_in_place_ref(t.second, u.second);
+}
+
+template<class T, class U>
+BOOST_CONTAINER_FORCEINLINE
+   typename dtl::enable_if_c
+      <  dtl::is_pair<typename dtl::remove_reference<T>::type>::value
+      && dtl::is_pair<typename dtl::remove_reference<U>::type>::value
+      , void>::type
+assign_in_place_ref(T &t, BOOST_RV_REF(U) u)
+{
+   assign_in_place_ref(t.first,  ::boost::move(u.first));
+   assign_in_place_ref(t.second, ::boost::move(u.second));
+}
+
 template<class DstIt, class InpIt>
 BOOST_CONTAINER_FORCEINLINE void assign_in_place(DstIt dest, InpIt source)
-{  *dest = *source;  }
+{  assign_in_place_ref(*dest, *source);  }
 
 template<class DstIt, class U>
 BOOST_CONTAINER_FORCEINLINE void assign_in_place(DstIt dest, value_init_construct_iterator<U>)
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/copy_move_algo.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/copy_move_algo.hpp
index 105faf606d..7c7d216feb 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/copy_move_algo.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/copy_move_algo.hpp
@@ -50,7 +50,7 @@
 #     pragma GCC diagnostic ignored "-Wstringop-overflow"
 #  endif
 //GCC 12 seems a bit confused about array access error with small_vector
-#  if defined(BOOST_GCC) && ((BOOST_GCC >= 120000) && (BOOST_GCC < 130000))
+#  if defined(BOOST_GCC) && (BOOST_GCC >= 110000)
 #     pragma GCC diagnostic ignored "-Wstringop-overread"
 #     pragma GCC diagnostic ignored "-Wstringop-overflow"
 #  endif
@@ -64,7 +64,7 @@ namespace dtl {
 template<class I>
 struct are_elements_contiguous
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 /////////////////////////
@@ -74,7 +74,7 @@ struct are_elements_contiguous
 template<class T>
 struct are_elements_contiguous<T*>
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 /////////////////////////
@@ -115,7 +115,7 @@ namespace dtl {
 template <class Pointer, bool IsConst>
 struct are_elements_contiguous<boost::container::vec_iterator<Pointer, IsConst> >
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 
@@ -126,7 +126,7 @@ struct are_elements_contiguous<boost::container::vec_iterator<Pointer, IsConst>
 template <class PointedType, class DifferenceType, class OffsetType, std::size_t OffsetAlignment>
 struct are_elements_contiguous< ::boost::interprocess::offset_ptr<PointedType, DifferenceType, OffsetType, OffsetAlignment> >
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 template <typename I, typename O>
@@ -185,20 +185,20 @@ struct has_single_value
    template <class U> static two test(int, ...);
    template <class U> static char test(int, const wrapper<U::single_value>*);
 public:
-   static const bool value = sizeof(test<T>(0, 0)) == 1;
+   BOOST_STATIC_CONSTEXPR bool value = sizeof(test<T>(0, 0)) == 1;
    void dummy() {}
 };
 
 template<class InsertionProxy, bool = has_single_value<InsertionProxy>::value>
 struct is_single_value_proxy_impl
 {
-   static const bool value = InsertionProxy::single_value;
+   BOOST_STATIC_CONSTEXPR bool value = InsertionProxy::single_value;
 };
 
 template<class InsertionProxy>
 struct is_single_value_proxy_impl<InsertionProxy, false>
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template<class InsertionProxy>
@@ -293,7 +293,7 @@ template <typename O>
 struct is_memzero_initializable
 {
    typedef typename ::boost::container::iterator_traits<O>::value_type value_type;
-   static const bool value = are_elements_contiguous<O>::value &&
+   BOOST_STATIC_CONSTEXPR bool value = are_elements_contiguous<O>::value &&
       (  dtl::is_integral<value_type>::value || dtl::is_enum<value_type>::value
       #if defined(BOOST_CONTAINER_MEMZEROED_POINTER_IS_NULL)
       || dtl::is_pointer<value_type>::value
@@ -1111,7 +1111,7 @@ inline typename dtl::disable_if_memtransfer_copy_assignable<F, G, void>::type
    boost::container::destroy_alloc_n(a, large_range_f, std::size_t(n_j - n_i));
 }
 
-static const std::size_t DeepSwapAllocNMaxStorage = std::size_t(1) << std::size_t(11); //2K bytes
+BOOST_CONTAINER_CONSTANT_VAR std::size_t DeepSwapAllocNMaxStorage = std::size_t(1) << std::size_t(11); //2K bytes
 
 template
    <std::size_t MaxTmpBytes
@@ -1496,8 +1496,8 @@ void expand_backward_forward_and_insert_alloc_move_backward
 {
    typedef std::size_t size_type;
    typedef typename allocator_traits<Allocator>::value_type value_type;
-   static const bool trivial_dctr_after_move = has_trivial_destructor_after_move<value_type>::value;
-   static const bool trivial_dctr = dtl::is_trivially_destructible<value_type>::value;
+   BOOST_STATIC_CONSTEXPR bool trivial_dctr_after_move = has_trivial_destructor_after_move<value_type>::value;
+   BOOST_STATIC_CONSTEXPR bool trivial_dctr = dtl::is_trivially_destructible<value_type>::value;
 
    typedef typename dtl::if_c
       <trivial_dctr
@@ -1796,8 +1796,8 @@ inline void expand_backward_forward_and_insert_alloc_move_forward
 {
    typedef std::size_t size_type;
    typedef typename allocator_traits<Allocator>::value_type value_type;
-   static const bool trivial_dctr_after_move = has_trivial_destructor_after_move<value_type>::value;
-   static const bool trivial_dctr = dtl::is_trivially_destructible<value_type>::value;
+   BOOST_STATIC_CONSTEXPR bool trivial_dctr_after_move = has_trivial_destructor_after_move<value_type>::value;
+   BOOST_STATIC_CONSTEXPR bool trivial_dctr = dtl::is_trivially_destructible<value_type>::value;
 
    typedef typename dtl::if_c
       <trivial_dctr
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/dispatch_uses_allocator.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/dispatch_uses_allocator.hpp
index 5bb7687d5a..343c512c79 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/dispatch_uses_allocator.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/dispatch_uses_allocator.hpp
@@ -62,7 +62,7 @@ namespace dtl {
       template<class X>
       static no_type test(...);
 
-      static const bool value = sizeof(test<T>(0)) == sizeof(yes_type);
+      BOOST_STATIC_CONSTEXPR bool value = sizeof(test<T>(0)) == sizeof(yes_type);
    };
 
    template <class T, class InnerAlloc, class ...Args>
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/flat_tree.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/flat_tree.hpp
index 5a14826ffd..98bd70280c 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/flat_tree.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/flat_tree.hpp
@@ -26,7 +26,6 @@
 
 #include <boost/move/utility_core.hpp>
 
-#include <boost/container/detail/pair.hpp>
 #include <boost/container/vector.hpp>
 #include <boost/container/allocator_traits.hpp>
 
@@ -43,11 +42,11 @@
 
 #include <boost/intrusive/detail/minimal_pair_header.hpp>      //pair
 
-#include <boost/move/make_unique.hpp>
 #include <boost/move/iterator.hpp>
 #include <boost/move/adl_move_swap.hpp>
 #include <boost/move/detail/iterator_to_raw_pointer.hpp>
 #include <boost/move/detail/force_ptr.hpp>
+#include <boost/move/detail/launder.hpp>
 #include <boost/move/algo/adaptive_sort.hpp>
 #include <boost/move/algo/detail/pdqsort.hpp>
 
@@ -583,7 +582,7 @@ class flat_tree
       (boost::container::dtl::, container_type
       ,stored_allocator_type, allocator_type)               stored_allocator_type;
 
-   static const bool has_stored_allocator_type =
+   BOOST_STATIC_CONSTEXPR bool has_stored_allocator_type =
       BOOST_INTRUSIVE_HAS_TYPE(boost::container::dtl::, container_type, stored_allocator_type);
 
    private:
@@ -955,6 +954,7 @@ class flat_tree
    template <class InIt>
    void insert_equal(ordered_range_t, InIt first, InIt last)
    {
+      BOOST_ASSERT((is_sorted)(first, last, this->priv_value_comp()));
       const bool value = boost::container::dtl::
          has_member_function_callable_with_merge_unique<container_type, InIt, InIt, value_compare>::value;
       (flat_tree_merge_equal)(this->m_data.m_seq, first, last, this->priv_value_comp(), dtl::bool_<value>());
@@ -963,6 +963,7 @@ class flat_tree
    template <class InIt>
    void insert_unique(ordered_unique_range_t, InIt first, InIt last)
    {
+      BOOST_ASSERT((is_sorted_and_unique)(this->m_data.m_seq.cbegin(), this->m_data.m_seq.cend(), this->priv_value_comp()));
       const bool value = boost::container::dtl::
          has_member_function_callable_with_merge_unique<container_type, InIt, InIt, value_compare>::value;
       (flat_tree_merge_unique)(this->m_data.m_seq, first, last, this->priv_value_comp(), dtl::bool_<value>());
@@ -975,8 +976,8 @@ class flat_tree
    {
       typename dtl::aligned_storage<sizeof(value_type), dtl::alignment_of<value_type>::value>::type v;
       get_stored_allocator_noconst_return_t a = this->get_stored_allocator();
-      stored_allocator_traits::construct(a, move_detail::force_ptr<value_type *>(&v), ::boost::forward<Args>(args)... );
-      value_type *pval = move_detail::force_ptr<value_type *>(&v);
+      stored_allocator_traits::construct(a, (value_type *)(&v), ::boost::forward<Args>(args)... );
+      value_type *pval = move_detail::launder_cast<value_type *>(&v);
       value_destructor<stored_allocator_type, value_type> d(a, *pval);
       return this->insert_unique(::boost::move(*pval));
    }
@@ -987,8 +988,8 @@ class flat_tree
       //hint checked in insert_unique
       typename dtl::aligned_storage<sizeof(value_type), dtl::alignment_of<value_type>::value>::type v;
       get_stored_allocator_noconst_return_t a = this->get_stored_allocator();
-      stored_allocator_traits::construct(a, move_detail::force_ptr<value_type *>(&v), ::boost::forward<Args>(args)... );
-      value_type *pval = move_detail::force_ptr<value_type *>(&v);
+      stored_allocator_traits::construct(a, (value_type*)(&v), ::boost::forward<Args>(args)... );
+      value_type *pval = move_detail::launder_cast<value_type *>(&v);
       value_destructor<stored_allocator_type, value_type> d(a, *pval);
       return this->insert_unique(hint, ::boost::move(*pval));
    }
@@ -998,8 +999,8 @@ class flat_tree
    {
       typename dtl::aligned_storage<sizeof(value_type), dtl::alignment_of<value_type>::value>::type v;
       get_stored_allocator_noconst_return_t a = this->get_stored_allocator();
-      stored_allocator_traits::construct(a, move_detail::force_ptr<value_type *>(&v), ::boost::forward<Args>(args)... );
-      value_type *pval = move_detail::force_ptr<value_type *>(&v);
+      stored_allocator_traits::construct(a, (value_type*)(&v), ::boost::forward<Args>(args)... );
+      value_type *pval = move_detail::launder_cast<value_type *>(&v);
       value_destructor<stored_allocator_type, value_type> d(a, *pval);
       return this->insert_equal(::boost::move(*pval));
    }
@@ -1010,8 +1011,8 @@ class flat_tree
       //hint checked in insert_equal
       typename dtl::aligned_storage<sizeof(value_type), dtl::alignment_of<value_type>::value>::type v;
       get_stored_allocator_noconst_return_t a = this->get_stored_allocator();
-      stored_allocator_traits::construct(a, move_detail::force_ptr<value_type *>(&v), ::boost::forward<Args>(args)... );
-      value_type *pval = move_detail::force_ptr<value_type *>(&v);
+      stored_allocator_traits::construct(a, (value_type*)(&v), ::boost::forward<Args>(args)... );
+      value_type *pval = move_detail::launder_cast<value_type *>(&v);
       value_destructor<stored_allocator_type, value_type> d(a, *pval);
       return this->insert_equal(hint, ::boost::move(*pval));
    }
@@ -1044,8 +1045,8 @@ class flat_tree
    {\
       typename dtl::aligned_storage<sizeof(value_type), dtl::alignment_of<value_type>::value>::type v;\
       get_stored_allocator_noconst_return_t a = this->get_stored_allocator();\
-      stored_allocator_traits::construct(a, move_detail::force_ptr<value_type *>(&v) BOOST_MOVE_I##N BOOST_MOVE_FWD##N);\
-      value_type *pval = move_detail::force_ptr<value_type *>(&v);\
+      stored_allocator_traits::construct(a, (value_type *)(&v) BOOST_MOVE_I##N BOOST_MOVE_FWD##N);\
+      value_type *pval = move_detail::launder_cast<value_type *>(&v);\
       value_destructor<stored_allocator_type, value_type> d(a, *pval);\
       return this->insert_unique(::boost::move(*pval));\
    }\
@@ -1055,8 +1056,8 @@ class flat_tree
    {\
       typename dtl::aligned_storage<sizeof(value_type), dtl::alignment_of<value_type>::value>::type v;\
       get_stored_allocator_noconst_return_t a = this->get_stored_allocator();\
-      stored_allocator_traits::construct(a, move_detail::force_ptr<value_type *>(&v) BOOST_MOVE_I##N BOOST_MOVE_FWD##N);\
-      value_type *pval = move_detail::force_ptr<value_type *>(&v);\
+      stored_allocator_traits::construct(a, (value_type *)(&v) BOOST_MOVE_I##N BOOST_MOVE_FWD##N);\
+      value_type *pval = move_detail::launder_cast<value_type *>(&v);\
       value_destructor<stored_allocator_type, value_type> d(a, *pval);\
       return this->insert_unique(hint, ::boost::move(*pval));\
    }\
@@ -1066,8 +1067,8 @@ class flat_tree
    {\
       typename dtl::aligned_storage<sizeof(value_type), dtl::alignment_of<value_type>::value>::type v;\
       get_stored_allocator_noconst_return_t a = this->get_stored_allocator();\
-      stored_allocator_traits::construct(a, move_detail::force_ptr<value_type *>(&v) BOOST_MOVE_I##N BOOST_MOVE_FWD##N);\
-      value_type *pval = move_detail::force_ptr<value_type *>(&v);\
+      stored_allocator_traits::construct(a, (value_type *)(&v) BOOST_MOVE_I##N BOOST_MOVE_FWD##N);\
+      value_type *pval = move_detail::launder_cast<value_type *>(&v);\
       value_destructor<stored_allocator_type, value_type> d(a, *pval);\
       return this->insert_equal(::boost::move(*pval));\
    }\
@@ -1077,8 +1078,8 @@ class flat_tree
    {\
       typename dtl::aligned_storage <sizeof(value_type), dtl::alignment_of<value_type>::value>::type v;\
       get_stored_allocator_noconst_return_t a = this->get_stored_allocator();\
-      stored_allocator_traits::construct(a, move_detail::force_ptr<value_type *>(&v) BOOST_MOVE_I##N BOOST_MOVE_FWD##N);\
-      value_type *pval = move_detail::force_ptr<value_type *>(&v);\
+      stored_allocator_traits::construct(a, (value_type *)(&v) BOOST_MOVE_I##N BOOST_MOVE_FWD##N);\
+      value_type *pval = move_detail::launder_cast<value_type *>(&v);\
       value_destructor<stored_allocator_type, value_type> d(a, *pval);\
       return this->insert_equal(hint, ::boost::move(*pval));\
    }\
@@ -1126,9 +1127,6 @@ class flat_tree
       return ret;
    }
 
-   inline iterator erase(const_iterator position)
-   {  return this->m_data.m_seq.erase(position);  }
-
    size_type erase(const key_type& k)
    {
       std::pair<iterator,iterator > itp = this->equal_range(k);
@@ -1148,6 +1146,40 @@ class flat_tree
       return ret;
    }
 
+   template <class K>
+   inline typename dtl::enable_if_c<
+      dtl::is_transparent<key_compare>::value &&      //transparent
+      !dtl::is_convertible<K, iterator>::value &&     //not convertible to iterator
+      !dtl::is_convertible<K, const_iterator>::value  //not convertible to const_iterator
+      , size_type>::type
+      erase(const K& k)
+   {
+      std::pair<iterator, iterator > itp = this->equal_range(k);
+      size_type ret = static_cast<size_type>(itp.second - itp.first);
+      if (ret) {
+         this->m_data.m_seq.erase(itp.first, itp.second);
+      }
+      return ret;
+   }
+
+   template <class K>
+   inline typename dtl::enable_if_c<
+      dtl::is_transparent<key_compare>::value &&      //transparent
+      !dtl::is_convertible<K, iterator>::value &&     //not convertible to iterator
+      !dtl::is_convertible<K, const_iterator>::value  //not convertible to const_iterator
+      , size_type>::type
+      erase_unique(const K& k)
+   {
+      const_iterator i = static_cast<const flat_tree&>(*this).find(k);
+      size_type ret = static_cast<size_type>(i != this->cend());
+      if (ret)
+         this->erase(i);
+      return ret;
+   }
+
+   inline iterator erase(const_iterator position)
+   {  return this->m_data.m_seq.erase(position);  }
+
    inline iterator erase(const_iterator first, const_iterator last)
    {  return this->m_data.m_seq.erase(first, last);  }
 
@@ -1700,7 +1732,7 @@ struct has_trivial_destructor_after_move<boost::container::dtl::flat_tree<T, Key
    typedef boost::container::dtl::flat_tree<T, KeyOfValue, Compare, AllocatorOrContainer> flat_tree;
    typedef typename flat_tree::container_type container_type;
    typedef typename flat_tree::key_compare key_compare;
-   static const bool value = ::boost::has_trivial_destructor_after_move<container_type>::value &&
+   BOOST_STATIC_CONSTEXPR bool value = ::boost::has_trivial_destructor_after_move<container_type>::value &&
                              ::boost::has_trivial_destructor_after_move<key_compare>::value;
 };
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/function_detector.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/function_detector.hpp
index 00caced5ba..33134cb06f 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/function_detector.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/function_detector.hpp
@@ -80,7 +80,7 @@ namespace function_detector {
       template <class U> \
       static NotFoundType Test( ... ); \
    public : \
-      static const int check = NotFound + (sizeof(Test<T>(0, 0)) - sizeof(NotFoundType));\
+      BOOST_STATIC_CONSTEXPR int check = NotFound + (sizeof(Test<T>(0, 0)) - sizeof(NotFoundType));\
    };\
 }}} //namespace boost::container::function_detector {
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/is_container.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/is_container.hpp
index 8ef0274d7a..fe44b46542 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/is_container.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/is_container.hpp
@@ -51,7 +51,7 @@ namespace dtl {
 template <class Container>
 struct is_container
 {
-   static const bool value =
+   BOOST_STATIC_CONSTEXPR bool value =
       boost::container::is_container_detail::
          has_member_function_callable_with_size <const Container>::value &&
       boost::container::is_container_detail::
@@ -61,7 +61,7 @@ struct is_container
 template <>
 struct is_container<void>
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/is_contiguous_container.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/is_contiguous_container.hpp
index 045de843a6..2688f809cf 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/is_contiguous_container.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/is_contiguous_container.hpp
@@ -51,7 +51,7 @@ namespace dtl {
 template <class Container>
 struct is_contiguous_container
 {
-   static const bool value =
+   BOOST_STATIC_CONSTEXPR bool value =
       boost::container::is_contiguous_container_detail::
          has_member_function_callable_with_data<Container>::value && 
       boost::container::is_contiguous_container_detail::
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/is_pair.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/is_pair.hpp
index 239e36e114..ddb63b68ff 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/is_pair.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/is_pair.hpp
@@ -61,25 +61,25 @@ struct pair;
 template <class T>
 struct is_pair
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template <class T1, class T2>
 struct is_pair< pair<T1, T2> >
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 template <class T1, class T2>
 struct is_pair< std::pair<T1, T2> >
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 template <class T>
 struct is_not_pair
 {
-   static const bool value = !is_pair<T>::value;
+   BOOST_STATIC_CONSTEXPR bool value = !is_pair<T>::value;
 };
 
 }  //namespace dtl {
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/iterators.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/iterators.hpp
index 57ffb0ced4..82daac4677 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/iterators.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/iterators.hpp
@@ -723,50 +723,50 @@ struct has_iterator_category
    template <typename X>
    static two test(int, ...);
 
-   static const bool value = (1 == sizeof(test<T>(0, 0)));
+   BOOST_STATIC_CONSTEXPR bool value = (1 == sizeof(test<T>(0, 0)));
 };
 
 
 template<class T, bool = has_iterator_category<T>::value >
 struct is_input_iterator
 {
-   static const bool value = is_same<typename T::iterator_category, std::input_iterator_tag>::value;
+   BOOST_STATIC_CONSTEXPR bool value = is_same<typename T::iterator_category, std::input_iterator_tag>::value;
 };
 
 template<class T>
 struct is_input_iterator<T, false>
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template<class T>
 struct is_not_input_iterator
 {
-   static const bool value = !is_input_iterator<T>::value;
+   BOOST_STATIC_CONSTEXPR bool value = !is_input_iterator<T>::value;
 };
 
 template<class T, bool = has_iterator_category<T>::value >
 struct is_forward_iterator
 {
-   static const bool value = is_same<typename T::iterator_category, std::forward_iterator_tag>::value;
+   BOOST_STATIC_CONSTEXPR bool value = is_same<typename T::iterator_category, std::forward_iterator_tag>::value;
 };
 
 template<class T>
 struct is_forward_iterator<T, false>
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template<class T, bool = has_iterator_category<T>::value >
 struct is_bidirectional_iterator
 {
-   static const bool value = is_same<typename T::iterator_category, std::bidirectional_iterator_tag>::value;
+   BOOST_STATIC_CONSTEXPR bool value = is_same<typename T::iterator_category, std::bidirectional_iterator_tag>::value;
 };
 
 template<class T>
 struct is_bidirectional_iterator<T, false>
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template<class IINodeType>
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/math_functions.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/math_functions.hpp
index b84ef6a12d..e9a9165241 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/math_functions.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/math_functions.hpp
@@ -100,7 +100,7 @@ struct upper_power_of_2_loop_ct
    template <Integer I, Integer P>
    struct apply
    {
-      static const Integer value =
+      BOOST_STATIC_CONSTEXPR Integer value =
          upper_power_of_2_loop_ct<Integer, (I > P*2)>::template apply<I, P*2>::value;
    };
 };
@@ -111,14 +111,14 @@ struct upper_power_of_2_loop_ct<Integer, false>
    template <Integer I, Integer P>
    struct apply
    {
-      static const Integer value = P;
+      BOOST_STATIC_CONSTEXPR Integer value = P;
    };
 };
 
 template <typename Integer, Integer I>
 struct upper_power_of_2_ct
 {
-   static const Integer value = upper_power_of_2_loop_ct<Integer, (I > 1)>::template apply<I, 2>::value;
+   BOOST_STATIC_CONSTEXPR Integer value = upper_power_of_2_loop_ct<Integer, (I > 1)>::template apply<I, 2>::value;
 };
 
 //This function uses binary search to discover the
@@ -144,27 +144,27 @@ inline std::size_t floor_log2 (std::size_t x)
 template<std::size_t I1, std::size_t I2>
 struct gcd_ct
 {
-   static const std::size_t Max = I1 > I2 ? I1 : I2;
-   static const std::size_t Min = I1 < I2 ? I1 : I2;
-   static const std::size_t value = gcd_ct<Min, Max % Min>::value;
+   BOOST_STATIC_CONSTEXPR std::size_t Max = I1 > I2 ? I1 : I2;
+   BOOST_STATIC_CONSTEXPR std::size_t Min = I1 < I2 ? I1 : I2;
+   BOOST_STATIC_CONSTEXPR std::size_t value = gcd_ct<Min, Max % Min>::value;
 };
 
 template<std::size_t I1>
 struct gcd_ct<I1, 0>
 {
-   static const std::size_t value = I1;
+   BOOST_STATIC_CONSTEXPR std::size_t value = I1;
 };
 
 template<std::size_t I1>
 struct gcd_ct<0, I1>
 {
-   static const std::size_t value = I1;
+   BOOST_STATIC_CONSTEXPR std::size_t value = I1;
 };
 
 template<std::size_t I1, std::size_t I2>
 struct lcm_ct
 {
-   static const std::size_t value = I1 * I2 / gcd_ct<I1, I2>::value;
+   BOOST_STATIC_CONSTEXPR std::size_t value = I1 * I2 / gcd_ct<I1, I2>::value;
 };
 
 } // namespace dtl
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/mpl.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/mpl.hpp
index ffae180c85..7662e4cc64 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/mpl.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/mpl.hpp
@@ -84,13 +84,13 @@ struct void_t { typedef void type; };
 template <class T, class=void>
 struct is_transparent_base
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template <class T>
 struct is_transparent_base<T, typename void_t<typename T::is_transparent>::type>
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 template <class T>
@@ -112,7 +112,7 @@ template<typename...> using variadic_void_t = void;
 template<typename Allocator, typename = void>
 struct is_allocator
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template <typename T>
@@ -123,7 +123,7 @@ struct is_allocator < Allocator,
    variadic_void_t< typename Allocator::value_type
                   , decltype(ctad_declval<Allocator&>().allocate(size_t{})) >>
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 template<class T>
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/multiallocation_chain.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/multiallocation_chain.hpp
index 749ef5a0ad..fa58a00bb3 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/multiallocation_chain.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/multiallocation_chain.hpp
@@ -25,15 +25,17 @@
 #include <boost/container/container_fwd.hpp>
 // container/detail
 #include <boost/move/detail/to_raw_pointer.hpp>
-#include <boost/container/detail/transform_iterator.hpp>
 #include <boost/container/detail/type_traits.hpp>
 #include <boost/container/detail/placement_new.hpp>
+#include <boost/container/detail/iterator.hpp>
 // intrusive
 #include <boost/intrusive/slist.hpp>
 #include <boost/intrusive/pointer_traits.hpp>
 #include <boost/intrusive/detail/twin.hpp>
 // move
 #include <boost/move/utility_core.hpp>
+#include <boost/move/detail/iterator_to_raw_pointer.hpp>
+
 
 namespace boost {
 namespace container {
@@ -187,15 +189,100 @@ class basic_multiallocation_chain
    }
 };
 
-template<class T>
-struct cast_functor
+template <class Iterator, class T>
+class multialloc_iterator
+   : public boost::container::iterator
+      < typename Iterator::iterator_category
+      , T
+      , typename Iterator::difference_type
+      , T*
+      , T&
+      >
 {
-   typedef typename dtl::add_reference<T>::type result_type;
-   template<class U>
-   result_type operator()(U &ptr) const
-   {  return *static_cast<T*>(static_cast<void*>(&ptr));  }
+   public:
+   inline explicit multialloc_iterator(const Iterator &it)
+      :  m_it(it)
+   {}
+
+   inline explicit multialloc_iterator()
+      :  m_it()
+   {}
+
+   //Constructors
+   inline multialloc_iterator& operator++()
+   { increment();   return *this;   }
+
+      inline multialloc_iterator operator++(int)
+   {
+      multialloc_iterator result (*this);
+      increment();
+      return result;
+   }
+
+   inline friend bool operator== (const multialloc_iterator& i, const multialloc_iterator& i2)
+   { return i.equal(i2); }
+
+   inline friend bool operator!= (const multialloc_iterator& i, const multialloc_iterator& i2)
+   { return !(i == i2); }
+
+   inline friend typename Iterator::difference_type operator- (const multialloc_iterator& i, const multialloc_iterator& i2)
+   { return i2.distance_to(i); }
+
+   //Arithmetic
+   inline multialloc_iterator& operator+=(typename Iterator::difference_type off)
+   {  this->advance(off); return *this;   }
+
+   inline multialloc_iterator operator+(typename Iterator::difference_type off) const
+   {
+      multialloc_iterator other(*this);
+      other.advance(off);
+      return other;
+   }
+
+   inline friend multialloc_iterator operator+(typename Iterator::difference_type off, const multialloc_iterator& right)
+   {  return right + off; }
+
+   inline multialloc_iterator& operator-=(typename Iterator::difference_type off)
+   {  this->advance(-off); return *this;   }
+
+   inline multialloc_iterator operator-(typename Iterator::difference_type off) const
+   {  return *this + (-off);  }
+
+   inline T& operator*() const
+   { return *this->operator->(); }
+
+   inline T* operator->() const
+   {  return static_cast<T*>(static_cast<void*>(boost::movelib::iterator_to_raw_pointer(m_it)));   }
+
+   inline Iterator & base()
+   {  return m_it;   }
+
+   inline const Iterator & base() const
+   {  return m_it;   }
+
+   private:
+   Iterator m_it;
+
+   inline void increment()
+   { ++m_it; }
+
+   inline void decrement()
+   { --m_it; }
+
+   inline bool equal(const multialloc_iterator &other) const
+   {  return m_it == other.m_it;   }
+
+   inline bool less(const multialloc_iterator &other) const
+   {  return other.m_it < m_it;   }
+
+   inline void advance(typename Iterator::difference_type n)
+   {  boost::container::iterator_advance(m_it, n); }
+
+   inline typename Iterator::difference_type distance_to(const multialloc_iterator &other)const
+   {  return boost::container::iterator_distance(other.m_it, m_it); }
 };
 
+
 template<class MultiallocationChain, class T>
 class transform_multiallocation_chain
    : public MultiallocationChain
@@ -217,9 +304,8 @@ class transform_multiallocation_chain
    {  return pointer_traits::static_cast_from(p);  }
 
    public:
-   typedef transform_iterator
-      < typename MultiallocationChain::iterator
-      , dtl::cast_functor <T> >                          iterator;
+   typedef multialloc_iterator
+      <typename MultiallocationChain::iterator, T>       iterator;
    typedef typename MultiallocationChain::size_type      size_type;
    typedef boost::intrusive::twin<pointer>               pointer_pair;
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/node_alloc_holder.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/node_alloc_holder.hpp
index 1ebf21ad84..32023e396a 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/node_alloc_holder.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/node_alloc_holder.hpp
@@ -31,12 +31,14 @@
 #include <boost/container/detail/construct_in_place.hpp>
 #include <boost/container/detail/destroyers.hpp>
 #include <boost/move/detail/iterator_to_raw_pointer.hpp>
+#include <boost/move/detail/launder.hpp>
 #include <boost/container/detail/mpl.hpp>
 #include <boost/container/detail/placement_new.hpp>
 #include <boost/move/detail/to_raw_pointer.hpp>
 #include <boost/container/detail/type_traits.hpp>
 #include <boost/container/detail/version_type.hpp>
 #include <boost/container/detail/is_pair.hpp>
+#include <boost/container/detail/pair.hpp>
 // intrusive
 #include <boost/intrusive/detail/mpl.hpp>
 #include <boost/intrusive/options.hpp>
@@ -119,16 +121,16 @@ struct base_node
    }
 
    inline T &get_data()
-   {  return *move_detail::force_ptr<T*>(this->m_storage.data);   }
+   {  return *move_detail::force_ptr<T*>(&this->m_storage);   }
 
    inline const T &get_data() const
-   {  return *move_detail::force_ptr<const T*>(this->m_storage.data);  }
+   {  return *move_detail::launder_cast<const T*>(&this->m_storage);  }
 
    inline internal_type &get_real_data()
-   {  return *move_detail::force_ptr<internal_type*>(this->m_storage.data);   }
+   {  return *move_detail::launder_cast<internal_type*>(&this->m_storage);   }
 
    inline const internal_type &get_real_data() const
-   {  return *move_detail::force_ptr<const internal_type*>(this->m_storage.data);  }
+   {  return *move_detail::launder_cast<const internal_type*>(&this->m_storage);  }
 
    #if defined(BOOST_CONTAINER_DISABLE_ALIASING_WARNING)
       #pragma GCC diagnostic pop
@@ -534,6 +536,19 @@ struct node_alloc_holder
       return this->icont().erase_and_dispose(k, chain_holder.get_chain_builder());
    }
 
+   template<class Key, class KeyCompare>
+   inline size_type erase_key(const Key& k, KeyCompare cmp, version_1)
+   {
+      return this->icont().erase_and_dispose(k, cmp, Destroyer(this->node_alloc()));
+   }
+
+   template<class Key, class KeyCompare>
+   inline size_type erase_key(const Key& k, KeyCompare cmp, version_2)
+   {
+      allocator_multialloc_chain_node_deallocator<NodeAlloc> chain_holder(this->node_alloc());
+      return this->icont().erase_and_dispose(k, cmp, chain_holder.get_chain_builder());
+   }
+
    protected:
    struct cloner
    {
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/node_pool.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/node_pool.hpp
index 6490772763..f0e1235335 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/node_pool.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/node_pool.hpp
@@ -52,7 +52,7 @@ class private_node_pool
 
    public:
    typedef typename base_t::multiallocation_chain multiallocation_chain;
-   static const std::size_t nodes_per_block = NodesPerBlock;
+   BOOST_STATIC_CONSTEXPR std::size_t nodes_per_block = NodesPerBlock;
 
    //!Constructor from a segment manager. Never throws
    private_node_pool()
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/pair.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/pair.hpp
index 58e560817a..0e84ffbf44 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/pair.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/pair.hpp
@@ -29,7 +29,7 @@
 #include <boost/container/detail/type_traits.hpp>
 #include <boost/container/detail/mpl.hpp>
 #include <boost/container/detail/std_fwd.hpp>
-#include <boost/container/detail/is_pair.hpp>
+#include <boost/container/detail/is_pair.hpp>   //Forward declares boost::tuples::tuple
 #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
 #  include <boost/container/detail/variadic_templates_tools.hpp>
 #endif
@@ -46,7 +46,7 @@ namespace pair_impl {
 template <class TupleClass>
 struct is_boost_tuple
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template <
@@ -56,7 +56,7 @@ template <
   class T9>
 struct is_boost_tuple< boost::tuples::tuple<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9> >
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 template<class Tuple>
@@ -67,13 +67,13 @@ struct disable_if_boost_tuple
 template<class T>
 struct is_tuple_null
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template<>
 struct is_tuple_null<boost::tuples::null_type>
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 }  //namespace detail {
@@ -482,7 +482,7 @@ inline void swap(pair<T1, T2>& x, pair<T1, T2>& y)
 template<class T1, class T2>
 struct has_move_emulation_enabled< ::boost::container::dtl::pair<T1, T2> >
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 #endif
@@ -497,7 +497,7 @@ struct is_class_or_union< ::boost::container::dtl::pair<T1, T2> >
 //This specialization is needed to avoid instantiation of pair in
 //is_class, and allow recursive maps.
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 template <class T1, class T2>
@@ -505,7 +505,7 @@ struct is_class_or_union< std::pair<T1, T2> >
 //This specialization is needed to avoid instantiation of pair in
 //is_class, and allow recursive maps.
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 template<class T>
@@ -516,7 +516,7 @@ struct is_union< ::boost::container::dtl::pair<T1, T2> >
 //This specialization is needed to avoid instantiation of pair in
 //is_class, and allow recursive maps.
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template <class T1, class T2>
@@ -524,7 +524,7 @@ struct is_union< std::pair<T1, T2> >
 //This specialization is needed to avoid instantiation of pair in
 //is_class, and allow recursive maps.
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template<class T>
@@ -535,7 +535,7 @@ struct is_class< ::boost::container::dtl::pair<T1, T2> >
 //This specialization is needed to avoid instantiation of pair in
 //is_class, and allow recursive maps.
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 template <class T1, class T2>
@@ -543,7 +543,7 @@ struct is_class< std::pair<T1, T2> >
 //This specialization is needed to avoid instantiation of pair in
 //is_class, and allow recursive maps.
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 
@@ -555,7 +555,7 @@ template<class A, class B>
 struct is_trivially_copy_assignable
    <boost::container::dtl::pair<A,B> >
 {
-   static const bool value = false ;
+   BOOST_STATIC_CONSTEXPR bool value = false ;
 };
 
 template<class T>
@@ -565,7 +565,7 @@ template<class A, class B>
 struct is_trivially_move_assignable
    <boost::container::dtl::pair<A,B> >
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template<class T>
@@ -574,7 +574,7 @@ struct is_trivially_copy_assignable;
 template<class A, class B>
 struct is_trivially_copy_constructible<boost::container::dtl::pair<A,B> >
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template<class T>
@@ -583,7 +583,7 @@ struct is_trivially_move_assignable;
 template<class A, class B>
 struct is_trivially_move_constructible<boost::container::dtl::pair<A,B> >
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template<class T>
@@ -592,7 +592,7 @@ struct is_trivially_destructible;
 template<class A, class B>
 struct is_trivially_destructible<boost::container::dtl::pair<A,B> >
 {
-   static const bool value = boost::move_detail::is_trivially_destructible<A>::value &&
+   BOOST_STATIC_CONSTEXPR bool value = boost::move_detail::is_trivially_destructible<A>::value &&
                              boost::move_detail::is_trivially_destructible<B>::value ;
 };
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/pool_common.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/pool_common.hpp
index f42c1dd4d2..8a570328fd 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/pool_common.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/pool_common.hpp
@@ -45,7 +45,7 @@ struct node_slist
 template<class T>
 struct is_stateless_segment_manager
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 }  //namespace dtl {
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/pool_common_alloc.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/pool_common_alloc.hpp
index f58c5e7a00..bc5cd7b72d 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/pool_common_alloc.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/pool_common_alloc.hpp
@@ -39,7 +39,7 @@ struct node_slist_helper
 struct fake_segment_manager
 {
    typedef void * void_pointer;
-   static const std::size_t PayloadPerAllocation = BOOST_CONTAINER_ALLOCATION_PAYLOAD;
+   BOOST_STATIC_CONSTEXPR std::size_t PayloadPerAllocation = BOOST_CONTAINER_ALLOCATION_PAYLOAD;
 
    typedef boost::container::dtl::
       basic_multiallocation_chain<void*>              multiallocation_chain;
@@ -90,7 +90,7 @@ template<>
 struct is_stateless_segment_manager
    <boost::container::dtl::fake_segment_manager>
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 }  //namespace dtl {
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/pool_resource.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/pool_resource.hpp
index 87eecacce1..a98dc70b63 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/pool_resource.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/pool_resource.hpp
@@ -31,11 +31,11 @@ namespace pmr {
 
 class pool_data_t;
 
-static const std::size_t pool_options_minimum_max_blocks_per_chunk = 1u;
-static const std::size_t pool_options_default_max_blocks_per_chunk = 32u;
-static const std::size_t pool_options_minimum_largest_required_pool_block =
+BOOST_CONTAINER_CONSTANT_VAR std::size_t pool_options_minimum_max_blocks_per_chunk = 1u;
+BOOST_CONTAINER_CONSTANT_VAR std::size_t pool_options_default_max_blocks_per_chunk = 32u;
+BOOST_CONTAINER_CONSTANT_VAR std::size_t pool_options_minimum_largest_required_pool_block =
    memory_resource::max_align > 2*sizeof(void*) ? memory_resource::max_align : 2*sizeof(void*);
-static const std::size_t pool_options_default_largest_required_pool_block =
+BOOST_CONTAINER_CONSTANT_VAR std::size_t pool_options_default_largest_required_pool_block =
    pool_options_minimum_largest_required_pool_block > 4096u
       ? pool_options_minimum_largest_required_pool_block : 4096u;
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/tree.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/tree.hpp
index f4a27b200e..1a3aa421a6 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/tree.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/tree.hpp
@@ -52,7 +52,6 @@
 #include <boost/move/detail/fwd_macros.hpp>
 #endif
 #include <boost/move/detail/move_helpers.hpp>
-#include <boost/move/detail/force_ptr.hpp>
 
 
 
@@ -252,13 +251,13 @@ struct intrusive_tree_type
 //Trait to detect manually rebalanceable tree types
 template<boost::container::tree_type_enum tree_type_value>
 struct is_manually_balanceable
-{  static const bool value = true;  };
+{  BOOST_STATIC_CONSTEXPR bool value = true;  };
 
 template<>  struct is_manually_balanceable<red_black_tree>
-{  static const bool value = false; };
+{  BOOST_STATIC_CONSTEXPR bool value = false; };
 
 template<>  struct is_manually_balanceable<avl_tree>
-{  static const bool value = false; };
+{  BOOST_STATIC_CONSTEXPR bool value = false; };
 
 //Proxy traits to implement different operations depending on the
 //is_manually_balanceable<>::value
@@ -689,40 +688,13 @@ class tree
                            boost::container::dtl::is_nothrow_move_assignable<Compare>::value)
    {
       if (BOOST_LIKELY(this != &x)) {
-         NodeAlloc &this_alloc = this->node_alloc();
-         NodeAlloc &x_alloc    = x.node_alloc();
-         const bool propagate_alloc = allocator_traits<NodeAlloc>::
-               propagate_on_container_move_assignment::value;
-         const bool allocators_equal = this_alloc == x_alloc; (void)allocators_equal;
-         //Resources can be transferred if both allocators are
-         //going to be equal after this function (either propagated or already equal)
-         if(propagate_alloc || allocators_equal){
-            //Destroy
-            this->clear();
-            //Move allocator if needed
-            this->AllocHolder::move_assign_alloc(x);
-            //Obtain resources
-            this->icont() = boost::move(x.icont());
-         }
-         //Else do a one by one move
-         else{
-            //Transfer all the nodes to a temporary tree
-            //If anything goes wrong, all the nodes will be destroyed
-            //automatically
-            Icont other_tree(::boost::move(this->icont()));
-
-            //Now recreate the source tree reusing nodes stored by other_tree
-            this->icont().clone_from
-               (::boost::move(x.icont())
-               , RecyclingCloner<AllocHolder, true>(*this, other_tree)
-               , Destroyer(this->node_alloc()));
-
-            //If there are remaining nodes, destroy them
-            NodePtr p;
-            while((p = other_tree.unlink_leftmost_without_rebalance())){
-               AllocHolder::destroy_node(p);
-            }
-         }
+         //We know resources can be transferred at comiple time if both allocators are
+         //always equal or the allocator is going to be propagated
+         const bool can_steal_resources_alloc
+            =  allocator_traits_type::propagate_on_container_move_assignment::value
+            || allocator_traits_type::is_always_equal::value;
+         dtl::bool_<can_steal_resources_alloc> flag;
+         this->priv_move_assign(boost::move(x), flag);
       }
       return *this;
    }
@@ -896,6 +868,42 @@ class tree
 
 
    private:
+   void priv_move_assign(BOOST_RV_REF(tree) x, dtl::bool_<true> /*steal_resources*/)
+   {
+      //Destroy objects but retain memory in case x reuses it in the future
+      this->clear();
+      //Move allocator if needed
+      this->AllocHolder::move_assign_alloc(x);
+      //Obtain resources
+      this->icont() = boost::move(x.icont());
+   }
+
+   void priv_move_assign(BOOST_RV_REF(tree) x, dtl::bool_<false> /*steal_resources*/)
+   {
+      //We can't guarantee a compile-time equal allocator or propagation so fallback to runtime
+      //Resources can be transferred if both allocators are equal
+      if (this->node_alloc() == x.node_alloc()) {
+         this->priv_move_assign(boost::move(x), dtl::true_());
+      }
+      else {
+         //Transfer all the nodes to a temporary tree
+         //If anything goes wrong, all the nodes will be destroyed
+         //automatically
+         Icont other_tree(::boost::move(this->icont()));
+
+         //Now recreate the source tree reusing nodes stored by other_tree
+         this->icont().clone_from
+         (::boost::move(x.icont())
+            , RecyclingCloner<AllocHolder, true>(*this, other_tree)
+            , Destroyer(this->node_alloc()));
+
+         //If there are remaining nodes, destroy them
+         NodePtr p;
+         while ((p = other_tree.unlink_leftmost_without_rebalance())) {
+            AllocHolder::destroy_node(p);
+         }
+      }
+   }
 
    template<class KeyConvertible, class M>
    iiterator priv_insert_or_assign_commit
@@ -1134,6 +1142,31 @@ class tree
       return ret;
    }
 
+   template <class K>
+   inline typename dtl::enable_if_c<
+      dtl::is_transparent<key_compare>::value &&      //transparent
+      !dtl::is_convertible<K, iterator>::value &&     //not convertible to iterator
+      !dtl::is_convertible<K, const_iterator>::value  //not convertible to const_iterator
+      , size_type>::type
+      erase(const K& k)
+   {  return AllocHolder::erase_key(k, KeyNodeCompare(key_comp()), alloc_version()); }
+
+   template <class K>
+   inline typename dtl::enable_if_c<
+      dtl::is_transparent<key_compare>::value &&      //transparent
+      !dtl::is_convertible<K, iterator>::value &&     //not convertible to iterator
+      !dtl::is_convertible<K, const_iterator>::value  //not convertible to const_iterator
+      , size_type>::type
+      erase_unique(const K& k)
+   {
+      iterator i = this->find(k);
+      size_type ret = static_cast<size_type>(i != this->end());
+
+      if (ret)
+         this->erase(i);
+      return ret;
+   }
+
    iterator erase(const_iterator first, const_iterator last)
    {
       BOOST_ASSERT(first == last || (first != this->cend() && (priv_is_linked)(first)));
@@ -1232,13 +1265,13 @@ class tree
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
       typename dtl::enable_if_transparent<key_compare, K, iterator>::type
          find(const K& k)
-   {  return iterator(this->icont().find(k, KeyNodeCompare()));  }
+   {  return iterator(this->icont().find(k, KeyNodeCompare(key_comp())));  }
 
    template <class K>
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
       typename dtl::enable_if_transparent<key_compare, K, const_iterator>::type
          find(const K& k) const
-   {  return const_iterator(this->non_const_icont().find(k, KeyNodeCompare()));  }
+   {  return const_iterator(this->non_const_icont().find(k, KeyNodeCompare(key_comp())));  }
 
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
       size_type count(const key_type& k) const
@@ -1248,7 +1281,7 @@ class tree
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
       typename dtl::enable_if_transparent<key_compare, K, size_type>::type
          count(const K& k) const
-   {  return size_type(this->icont().count(k, KeyNodeCompare())); }
+   {  return size_type(this->icont().count(k, KeyNodeCompare(key_comp()))); }
 
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
       bool contains(const key_type& x) const
@@ -1272,13 +1305,13 @@ class tree
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
       typename dtl::enable_if_transparent<key_compare, K, iterator>::type
          lower_bound(const K& k)
-   {  return iterator(this->icont().lower_bound(k, KeyNodeCompare()));  }
+   {  return iterator(this->icont().lower_bound(k, KeyNodeCompare(key_comp())));  }
 
    template <class K>
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
       typename dtl::enable_if_transparent<key_compare, K, const_iterator>::type
          lower_bound(const K& k) const
-   {  return const_iterator(this->non_const_icont().lower_bound(k, KeyNodeCompare()));  }
+   {  return const_iterator(this->non_const_icont().lower_bound(k, KeyNodeCompare(key_comp())));  }
 
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
       iterator upper_bound(const key_type& k)
@@ -1292,13 +1325,13 @@ class tree
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
       typename dtl::enable_if_transparent<key_compare, K, iterator>::type
          upper_bound(const K& k)
-   {  return iterator(this->icont().upper_bound(k, KeyNodeCompare()));   }
+   {  return iterator(this->icont().upper_bound(k, KeyNodeCompare(key_comp())));   }
 
    template <class K>
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
       typename dtl::enable_if_transparent<key_compare, K, const_iterator>::type
          upper_bound(const K& k) const
-   {  return const_iterator(this->non_const_icont().upper_bound(k, KeyNodeCompare()));  }
+   {  return const_iterator(this->non_const_icont().upper_bound(k, KeyNodeCompare(key_comp())));  }
 
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
       std::pair<iterator,iterator> equal_range(const key_type& k)
@@ -1322,7 +1355,7 @@ class tree
          equal_range(const K& k)
    {
       std::pair<iiterator, iiterator> ret =
-         this->icont().equal_range(k, KeyNodeCompare());
+         this->icont().equal_range(k, KeyNodeCompare(key_comp()));
       return std::pair<iterator,iterator>(iterator(ret.first), iterator(ret.second));
    }
 
@@ -1332,7 +1365,7 @@ class tree
          equal_range(const K& k) const
    {
       std::pair<iiterator, iiterator> ret =
-         this->non_const_icont().equal_range(k, KeyNodeCompare());
+         this->non_const_icont().equal_range(k, KeyNodeCompare(key_comp()));
       return std::pair<const_iterator,const_iterator>
          (const_iterator(ret.first), const_iterator(ret.second));
    }
@@ -1360,7 +1393,7 @@ class tree
          lower_bound_range(const K& k)
    {
       std::pair<iiterator, iiterator> ret =
-         this->icont().lower_bound_range(k, KeyNodeCompare());
+         this->icont().lower_bound_range(k, KeyNodeCompare(key_comp()));
       return std::pair<iterator,iterator>(iterator(ret.first), iterator(ret.second));
    }
 
@@ -1370,7 +1403,7 @@ class tree
          lower_bound_range(const K& k) const
    {
       std::pair<iiterator, iiterator> ret =
-         this->non_const_icont().lower_bound_range(k, KeyNodeCompare());
+         this->non_const_icont().lower_bound_range(k, KeyNodeCompare(key_comp()));
       return std::pair<const_iterator,const_iterator>
          (const_iterator(ret.first), const_iterator(ret.second));
    }
@@ -1425,9 +1458,10 @@ struct has_trivial_destructor_after_move
 {
    typedef typename ::boost::container::dtl::tree<T, KeyOfValue, Compare, Allocator, Options>::allocator_type allocator_type;
    typedef typename ::boost::container::allocator_traits<allocator_type>::pointer pointer;
-   static const bool value = ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
-                             ::boost::has_trivial_destructor_after_move<pointer>::value &&
-                             ::boost::has_trivial_destructor_after_move<Compare>::value;
+   BOOST_STATIC_CONSTEXPR bool value =
+      ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
+      ::boost::has_trivial_destructor_after_move<pointer>::value &&
+      ::boost::has_trivial_destructor_after_move<Compare>::value;
 };
 
 } //namespace boost  {
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/version_type.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/version_type.hpp
index 389606a567..e02244ac84 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/version_type.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/version_type.hpp
@@ -57,20 +57,20 @@ struct has_version
    template <class U> static two test(...);
    template <class U> static char test(const typename U::version*);
    public:
-   static const bool value = sizeof(test<T>(0)) == 1;
+   BOOST_STATIC_CONSTEXPR bool value = sizeof(test<T>(0)) == 1;
    void dummy(){}
 };
 
 template <class T, bool = has_version<T>::value>
 struct version
 {
-   static const unsigned value = 1;
+   BOOST_STATIC_CONSTEXPR unsigned value = 1;
 };
 
 template <class T>
 struct version<T, true>
 {
-   static const unsigned value = extract_version<T>::type::value;
+   BOOST_STATIC_CONSTEXPR unsigned value = extract_version<T>::type::value;
 };
 
 }  //namespace impl
@@ -83,7 +83,7 @@ struct version
 template<class T, unsigned N>
 struct is_version
 {
-   static const bool value =
+   BOOST_STATIC_CONSTEXPR bool value =
       is_same< typename version<T>::type, integral_constant<unsigned, N> >::value;
 };
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/detail/workaround.hpp b/src/cxx_supportlib/vendor-modified/boost/container/detail/workaround.hpp
index 23342bb0d1..055cf24d3a 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/detail/workaround.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/detail/workaround.hpp
@@ -230,4 +230,16 @@ namespace boost {
 #     define BOOST_CONTAINER_STATIC_ASSERT_MSG( B, Msg ) BOOST_CONTAINER_STATIC_ASSERT( B )
 #endif
 
+#if !defined(BOOST_NO_CXX17_INLINE_VARIABLES)
+#  define BOOST_CONTAINER_CONSTANT_VAR BOOST_INLINE_CONSTEXPR
+#else
+#  define BOOST_CONTAINER_CONSTANT_VAR static BOOST_CONSTEXPR_OR_CONST
+#endif
+
+#if defined(__GNUC__) && ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) >= 40600)
+#define BOOST_CONTAINER_GCC_COMPATIBLE_HAS_DIAGNOSTIC_IGNORED
+#elif defined(__clang__)
+#define BOOST_CONTAINER_GCC_COMPATIBLE_HAS_DIAGNOSTIC_IGNORED
+#endif
+
 #endif   //#ifndef BOOST_CONTAINER_DETAIL_WORKAROUND_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/devector.hpp b/src/cxx_supportlib/vendor-modified/boost/container/devector.hpp
index 5195fa0ec3..9b1f643090 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/devector.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/devector.hpp
@@ -46,7 +46,6 @@
 #include <boost/move/utility_core.hpp>
 #include <boost/move/detail/to_raw_pointer.hpp>
 #include <boost/move/algo/detail/merge.hpp>
-#include <boost/move/detail/force_ptr.hpp>
 
 //std
 #if !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST)
@@ -148,7 +147,7 @@ class devector
    typedef typename get_devector_opt<Options, alloc_size_type>::type             options_type;
    typedef typename options_type::growth_factor_type                             growth_factor_type;
    typedef typename options_type::stored_size_type                               stored_size_type;
-   static const std::size_t devector_min_free_fraction =
+   BOOST_STATIC_CONSTEXPR std::size_t devector_min_free_fraction =
       options_type::free_fraction;
 
    #endif // ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
@@ -513,20 +512,21 @@ class devector
       const devector &x = rhs;
       if (this == &x) { return *this; } // skip self
 
-      BOOST_IF_CONSTEXPR(allocator_traits_type::propagate_on_container_copy_assignment::value)
+      const bool do_propagate = allocator_traits_type::propagate_on_container_copy_assignment::value;
+      BOOST_IF_CONSTEXPR(do_propagate)
       {
-            allocator_type &this_alloc = this->get_allocator_ref();
-            const allocator_type &other_alloc = x.get_allocator_ref();
-            if (this_alloc != other_alloc)
-            {
-               // new allocator cannot free existing storage
-               this->clear();
-               this->deallocate_buffer();
-               m_.capacity = 0u;
-               m_.buffer = pointer();
-            }
-
-            this_alloc = other_alloc;
+         allocator_type &this_alloc = this->get_allocator_ref();
+         const allocator_type &other_alloc = x.get_allocator_ref();
+         if (this_alloc != other_alloc)
+         {
+            // new allocator cannot free existing storage
+            this->clear();
+            this->deallocate_buffer();
+            m_.capacity = 0u;
+            m_.buffer = pointer();
+         }
+         dtl::bool_<do_propagate> flag;
+         dtl::assign_alloc(this_alloc, other_alloc, flag);
       }
 
       size_type n = x.size();
@@ -566,53 +566,16 @@ class devector
       BOOST_NOEXCEPT_IF(allocator_traits_type::propagate_on_container_move_assignment::value
                                  || allocator_traits_type::is_always_equal::value)
    {
-      BOOST_CONSTEXPR_OR_CONST bool copy_alloc = allocator_traits_type::propagate_on_container_move_assignment::value;
-
-      BOOST_IF_CONSTEXPR (copy_alloc || get_allocator_ref() == x.get_allocator_ref())
-      {
-         this->clear();
-         this->deallocate_buffer();
-
-         if (copy_alloc)
-         {
-            this->get_allocator_ref() = boost::move(x.get_allocator_ref());
-         }
-
-         m_.capacity = x.m_.capacity;
-         m_.buffer = x.m_.buffer;
-         m_.front_idx = x.m_.front_idx;
-         m_.back_idx = x.m_.back_idx;
-
-         // leave x in valid state
-         x.m_.capacity = 0u;
-         x.m_.buffer = pointer();
-         x.m_.back_idx = x.m_.front_idx = 0;
+      if (BOOST_LIKELY(this != &x)) {
+         //We know resources can be transferred at comiple time if both allocators are
+         //always equal or the allocator is going to be propagated
+         const bool can_steal_resources_alloc
+            = allocator_traits_type::propagate_on_container_move_assignment::value
+            || allocator_traits_type::is_always_equal::value;
+         dtl::bool_<can_steal_resources_alloc> flag;
+         this->priv_move_assign(boost::move(x), flag);
       }
-      else
-      {
-         // if the allocator shouldn't be copied and they do not compare equal
-         // we can't steal memory.
-
-         move_iterator<iterator> xbegin = boost::make_move_iterator(x.begin());
-         move_iterator<iterator> xend = boost::make_move_iterator(x.end());
-
-         if (copy_alloc)
-         {
-            get_allocator_ref() = boost::move(x.get_allocator_ref());
-         }
-
-         if (m_.capacity >= x.size())
-         {
-            overwrite_buffer(xbegin, xend);
-         }
-         else
-         {
-            allocate_and_copy_range(xbegin, xend);
-         }
-      }
-
       BOOST_ASSERT(invariants_ok());
-
       return *this;
    }
 
@@ -1310,6 +1273,78 @@ class devector
       return m_.buffer[m_.front_idx + n];
    }
 
+   //! <b>Requires</b>: size() >= n.
+   //!
+   //! <b>Effects</b>: Returns an iterator to the nth element
+   //!   from the beginning of the container. Returns end()
+   //!   if n == size().
+   //!
+   //! <b>Throws</b>: Nothing.
+   //!
+   //! <b>Complexity</b>: Constant.
+   //!
+   //! <b>Note</b>: Non-standard extension
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      iterator nth(size_type n) BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      BOOST_ASSERT(n <= size());
+      return iterator(m_.buffer + (m_.front_idx + n));
+   }
+
+   //! <b>Requires</b>: size() >= n.
+   //!
+   //! <b>Effects</b>: Returns a const_iterator to the nth element
+   //!   from the beginning of the container. Returns end()
+   //!   if n == size().
+   //!
+   //! <b>Throws</b>: Nothing.
+   //!
+   //! <b>Complexity</b>: Constant.
+   //!
+   //! <b>Note</b>: Non-standard extension
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      const_iterator nth(size_type n) const BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      BOOST_ASSERT(n <= size());
+      return const_iterator(m_.buffer + (m_.front_idx + n));
+   }
+
+   //! <b>Requires</b>: begin() <= p <= end().
+   //!
+   //! <b>Effects</b>: Returns the index of the element pointed by p
+   //!   and size() if p == end().
+   //!
+   //! <b>Throws</b>: Nothing.
+   //!
+   //! <b>Complexity</b>: Constant.
+   //!
+   //! <b>Note</b>: Non-standard extension
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      size_type index_of(iterator p) BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      BOOST_ASSERT(p >= begin());
+      BOOST_ASSERT(p <= end());
+      return static_cast<size_type>(p - this->begin());
+   }
+
+   //! <b>Requires</b>: begin() <= p <= end().
+   //!
+   //! <b>Effects</b>: Returns the index of the element pointed by p
+   //!   and size() if p == end().
+   //!
+   //! <b>Throws</b>: Nothing.
+   //!
+   //! <b>Complexity</b>: Constant.
+   //!
+   //! <b>Note</b>: Non-standard extension
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
+      size_type index_of(const_iterator p) const BOOST_NOEXCEPT_OR_NOTHROW
+   {
+      BOOST_ASSERT(p >= cbegin());
+      BOOST_ASSERT(p <= cend());
+      return static_cast<size_type>(p - this->cbegin());
+   }
+
    /**
    * **Returns**: A reference to the `n`th element in the devector.
    *
@@ -2137,6 +2172,53 @@ class devector
 
    private:
 
+   void priv_move_assign(BOOST_RV_REF(devector) x, dtl::bool_<true> /*steal_resources*/)
+   {
+      this->clear();
+      this->deallocate_buffer();
+
+      //Move allocator if needed
+      dtl::bool_<allocator_traits_type::
+         propagate_on_container_move_assignment::value> flag;
+      dtl::move_alloc(this->get_allocator_ref(), x.get_allocator_ref(), flag);
+
+      m_.capacity = x.m_.capacity;
+      m_.buffer = x.m_.buffer;
+      m_.front_idx = x.m_.front_idx;
+      m_.back_idx = x.m_.back_idx;
+
+      // leave x in valid state
+      x.m_.capacity = 0u;
+      x.m_.buffer = pointer();
+      x.m_.back_idx = x.m_.front_idx = 0;
+   }
+
+   void priv_move_assign(BOOST_RV_REF(devector) x, dtl::bool_<false> /*steal_resources*/)
+   {
+      //We can't guarantee a compile-time equal allocator or propagation so fallback to runtime
+      //Resources can be transferred if both allocators are equal
+      if (get_allocator_ref() == x.get_allocator_ref()) {
+         this->priv_move_assign(boost::move(x), dtl::true_());
+      }
+      else {
+         // We can't steal memory.
+         move_iterator<iterator> xbegin = boost::make_move_iterator(x.begin());
+         move_iterator<iterator> xend = boost::make_move_iterator(x.end());
+
+         //Move allocator if needed
+         dtl::bool_<allocator_traits_type::
+            propagate_on_container_move_assignment::value> flag;
+         dtl::move_alloc(this->get_allocator_ref(), x.get_allocator_ref(), flag);
+
+         if (m_.capacity >= x.size()) {
+            overwrite_buffer(xbegin, xend);
+         }
+         else {
+            allocate_and_copy_range(xbegin, xend);
+         }
+      }
+   }
+
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
    size_type pos_to_index(const_iterator i) const 
    {
@@ -2653,10 +2735,7 @@ class devector
       size_type const cap = m_.capacity;
       //Test if enough free memory would be left
       if (free_cap >= n && (free_cap - n) >= cap/devector_min_free_fraction) {
-         //Make sure relocation is happening because there was no enough space
          size_type const old_size = this->size();
-         BOOST_ASSERT(should_move_back(p) ? (back_free_cap < n) : (front_free_cap < n));
-
          T* const raw_pos = const_cast<T*>(boost::movelib::to_raw_pointer(p));
          size_type const new_size = old_size + n;
          size_type const new_front_idx = (cap - new_size) / 2u;
@@ -2948,8 +3027,9 @@ struct has_trivial_destructor_after_move<boost::container::devector<T, Allocator
 {
     typedef typename boost::container::devector<T, Allocator, Options>::allocator_type allocator_type;
     typedef typename ::boost::container::allocator_traits<allocator_type>::pointer pointer;
-    static const bool value = ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
-                                           ::boost::has_trivial_destructor_after_move<pointer>::value;
+    BOOST_STATIC_CONSTEXPR bool value =
+      ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
+      ::boost::has_trivial_destructor_after_move<pointer>::value;
 };
 
 }
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/flat_map.hpp b/src/cxx_supportlib/vendor-modified/boost/container/flat_map.hpp
index b092fb2124..cf6d650354 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/flat_map.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/flat_map.hpp
@@ -31,6 +31,7 @@
 #include <boost/container/detail/mpl.hpp>
 #include <boost/container/detail/algorithm.hpp> //equal()
 #include <boost/container/detail/container_or_allocator_rebind.hpp>
+#include <boost/container/detail/pair.hpp>
 // move
 #include <boost/move/utility_core.hpp>
 #include <boost/move/traits.hpp>
@@ -44,10 +45,22 @@
 #include <boost/intrusive/detail/minimal_pair_header.hpp>      //pair
 #include <boost/intrusive/detail/minimal_less_equal_header.hpp>//less, equal
 
+
 #if !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST)
 #include <initializer_list>
 #endif
 
+#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
+#define BOOST_CONTAINER_STD_PAIR_IS_MOVABLE
+#endif
+
+//for C++03 compilers, were type-puning is the only option for std::pair
+//disable strict aliasing to reduce problems.
+#if defined(BOOST_GCC) && (BOOST_GCC >= 100000) && !defined(BOOST_CONTAINER_STD_PAIR_IS_MOVABLE)
+#pragma GCC push_options
+#pragma GCC optimize("no-strict-aliasing")
+#endif
+
 namespace boost {
 namespace container {
 
@@ -58,21 +71,37 @@ class flat_multimap;
 
 namespace dtl{
 
+#if defined(BOOST_CONTAINER_STD_PAIR_IS_MOVABLE)
 template<class D, class S>
 BOOST_CONTAINER_FORCEINLINE static D &force(S &s)
-{  return *move_detail::force_ptr<D*>(&s); }
+{  return s; }
 
 template<class D, class S>
 BOOST_CONTAINER_FORCEINLINE static const D &force(const S &s)
-{  return *move_detail::force_ptr<const D*>(&s); }
+{  return s; }
+
+template<class D>
+BOOST_CONTAINER_FORCEINLINE static D force_copy(D s)
+{  return s; }
+
+#else //!BOOST_CONTAINER_DOXYGEN_INVOKED
+
+template<class D, class S>
+BOOST_CONTAINER_FORCEINLINE static D &force(S &s)
+{  return *move_detail::launder_cast<D*>(&s); }
+
+template<class D, class S>
+BOOST_CONTAINER_FORCEINLINE static const D &force(const S &s)
+{  return *move_detail::launder_cast<const D*>(&s); }
 
 template<class D, class S>
 BOOST_CONTAINER_FORCEINLINE static D force_copy(const S &s)
 {
-   const D *const vp = move_detail::force_ptr<const D *>(&s);
+   const D *const vp = move_detail::launder_cast<const D *>(&s);
    D ret_val(*vp);
    return ret_val;
 }
+#endif   //BOOST_CONTAINER_DOXYGEN_INVOKED
 
 }  //namespace dtl{
 
@@ -118,18 +147,27 @@ class flat_map
    private:
    BOOST_COPYABLE_AND_MOVABLE(flat_map)
    //This is the tree that we should store if pair was movable
+   typedef std::pair<Key, T> std_pair_t;
    typedef dtl::flat_tree<
-                           std::pair<Key, T>,
+                           std_pair_t,
                            dtl::select1st<Key>,
                            Compare,
                            AllocatorOrContainer> tree_t;
 
    //This is the real tree stored here. It's based on a movable pair
+   typedef dtl::pair<Key, T> dtl_pair_t;
+
+   #ifdef BOOST_CONTAINER_STD_PAIR_IS_MOVABLE
+   typedef std_pair_t impl_pair_t;
+   #else
+   typedef dtl_pair_t impl_pair_t;
+   #endif
+
    typedef dtl::flat_tree<
-                           dtl::pair<Key, T>,
+                           impl_pair_t,
                            dtl::select1st<Key>,
                            Compare,
-                           typename dtl::container_or_allocator_rebind<AllocatorOrContainer, dtl::pair<Key, T> >::type
+                           typename dtl::container_or_allocator_rebind<AllocatorOrContainer, impl_pair_t >::type
                            > impl_tree_t;
    impl_tree_t m_flat_tree;  // flat tree representing flat_map
 
@@ -851,7 +889,7 @@ class flat_map
    //! @copydoc ::boost::container::flat_set::nth(size_type) const
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
       const_iterator nth(size_type n) const BOOST_NOEXCEPT_OR_NOTHROW
-   {  return dtl::force_copy<iterator>(m_flat_tree.nth(n));  }
+   {  return dtl::force_copy<const_iterator>(m_flat_tree.nth(n));  }
 
    //! @copydoc ::boost::container::flat_set::index_of(iterator)
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
@@ -1099,7 +1137,7 @@ class flat_map
    template <class Pair>
    inline BOOST_CONTAINER_DOC1ST
          ( std::pair<iterator BOOST_MOVE_I bool>
-         , typename dtl::enable_if_c<dtl::is_convertible<Pair BOOST_MOVE_I impl_value_type>::value
+         , typename dtl::enable_if_c<dtl::is_convertible<Pair BOOST_MOVE_I dtl_pair_t>::value
             BOOST_MOVE_I std::pair<iterator BOOST_MOVE_I bool> >::type)
       insert(BOOST_FWD_REF(Pair) x)
    {
@@ -1153,7 +1191,7 @@ class flat_map
    template <class Pair>
    inline BOOST_CONTAINER_DOC1ST
          ( iterator
-         , typename dtl::enable_if_c<dtl::is_convertible<Pair BOOST_MOVE_I impl_value_type>::value
+         , typename dtl::enable_if_c<dtl::is_convertible<Pair BOOST_MOVE_I dtl_pair_t>::value
             BOOST_MOVE_I iterator>::type)
       insert(const_iterator p, BOOST_FWD_REF(Pair) x)
    {
@@ -1277,6 +1315,23 @@ class flat_map
    inline size_type erase(const key_type& x)
       { return m_flat_tree.erase_unique(x); }
 
+   //! <b>Requires</b>: This overload is available only if
+   //! key_compare::is_transparent exists.
+   //!
+   //! <b>Effects</b>: If present, erases the element in the container with key equivalent to x.
+   //!
+   //! <b>Returns</b>: Returns the number of erased elements (0/1).
+   template <class K>
+   inline BOOST_CONTAINER_DOC1ST
+   (size_type
+      , typename dtl::enable_if_c<
+      dtl::is_transparent<key_compare>::value &&                  //transparent
+      !dtl::is_convertible<K BOOST_MOVE_I iterator>::value &&     //not convertible to iterator
+      !dtl::is_convertible<K BOOST_MOVE_I const_iterator>::value  //not convertible to const_iterator
+      BOOST_MOVE_I size_type>::type)
+      erase(const K& x)
+   {  return m_flat_tree.erase_unique(x); }
+
    //! <b>Effects</b>: Erases all the elements in the range [first, last).
    //!
    //! <b>Returns</b>: Returns last.
@@ -1637,7 +1692,7 @@ class flat_map
       if (i == end() || key_comp()(k, (*i).first)){
          dtl::value_init<mapped_type> m;
          impl_value_type v(k, ::boost::move(m.m_t));
-         i = this->insert(i, ::boost::move(v));
+         i = dtl::force_copy<iterator>(this->m_flat_tree.insert_equal(::boost::move(v)));
       }
       return (*i).second;
    }
@@ -1646,10 +1701,10 @@ class flat_map
       key_type &k = mk;
       iterator i = this->lower_bound(k);
       // i->first is greater than or equivalent to k.
-      if (i == end() || key_comp()(k, (*i).first)){
+      if (i == end() || key_comp()(k, (*i).first)) {
          dtl::value_init<mapped_type> m;
          impl_value_type v(::boost::move(k), ::boost::move(m.m_t));
-         i = this->insert(i, ::boost::move(v));
+         i = dtl::force_copy<iterator>(this->m_flat_tree.insert_equal(::boost::move(v)));
       }
       return (*i).second;
    }
@@ -1729,10 +1784,10 @@ flat_map(ordered_unique_range_t, InputIterator, InputIterator, Compare const&, A
 template <class Key, class T, class Compare, class AllocatorOrContainer>
 struct has_trivial_destructor_after_move<boost::container::flat_map<Key, T, Compare, AllocatorOrContainer> >
 {
-   typedef ::boost::container::dtl::pair<Key, T> value_t;
+   typedef typename boost::container::flat_map<Key, T, Compare, AllocatorOrContainer>::value_type value_t;
    typedef typename ::boost::container::dtl::container_or_allocator_rebind<AllocatorOrContainer, value_t>::type alloc_or_cont_t;
    typedef ::boost::container::dtl::flat_tree<value_t,::boost::container::dtl::select1st<Key>, Compare, alloc_or_cont_t> tree;
-   static const bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
+   BOOST_STATIC_CONSTEXPR bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
 };
 
 namespace container {
@@ -1777,17 +1832,24 @@ class flat_multimap
    #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
    private:
    BOOST_COPYABLE_AND_MOVABLE(flat_multimap)
+   typedef std::pair<Key, T> std_pair_t;
    typedef dtl::flat_tree<
-                           std::pair<Key, T>,
+                           std_pair_t,
                            dtl::select1st<Key>,
                            Compare,
                            AllocatorOrContainer> tree_t;
    //This is the real tree stored here. It's based on a movable pair
+   typedef dtl::pair<Key, T> dtl_pair_t;
+   #ifdef BOOST_CONTAINER_STD_PAIR_IS_MOVABLE
+   typedef std_pair_t impl_pair_t;
+   #else
+   typedef dtl_pair_t impl_pair_t;
+   #endif
    typedef dtl::flat_tree<
-                           dtl::pair<Key, T>,
+                           impl_pair_t,
                            dtl::select1st<Key>,
                            Compare,
-                           typename dtl::container_or_allocator_rebind<AllocatorOrContainer, dtl::pair<Key, T> >::type
+                           typename dtl::container_or_allocator_rebind<AllocatorOrContainer, impl_pair_t >::type
                            > impl_tree_t;
    impl_tree_t m_flat_tree;  // flat tree representing flat_map
 
@@ -2388,7 +2450,7 @@ class flat_multimap
    //! @copydoc ::boost::container::flat_set::nth(size_type) const
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
    const_iterator nth(size_type n) const BOOST_NOEXCEPT_OR_NOTHROW
-   {  return dtl::force_copy<iterator>(m_flat_tree.nth(n));  }
+   {  return dtl::force_copy<const_iterator>(m_flat_tree.nth(n));  }
 
    //! @copydoc ::boost::container::flat_set::index_of(iterator)
    BOOST_CONTAINER_ATTRIBUTE_NODISCARD inline
@@ -2477,7 +2539,7 @@ class flat_multimap
    template<class Pair>
    inline BOOST_CONTAINER_DOC1ST
          ( iterator
-         , typename dtl::enable_if_c<dtl::is_convertible<Pair BOOST_MOVE_I impl_value_type>::value
+         , typename dtl::enable_if_c<dtl::is_convertible<Pair BOOST_MOVE_I dtl_pair_t>::value
             BOOST_MOVE_I iterator >::type)
       insert(BOOST_FWD_REF(Pair) x)
    { return dtl::force_copy<iterator>(m_flat_tree.emplace_equal(boost::forward<Pair>(x))); }
@@ -2514,7 +2576,7 @@ class flat_multimap
    template<class Pair>
    inline BOOST_CONTAINER_DOC1ST
          ( iterator
-         , typename dtl::enable_if_c<dtl::is_convertible<Pair BOOST_MOVE_I impl_value_type>::value
+         , typename dtl::enable_if_c<dtl::is_convertible<Pair BOOST_MOVE_I dtl_pair_t>::value
             BOOST_MOVE_I iterator>::type)
       insert(const_iterator p, BOOST_FWD_REF(Pair) x)
    {
@@ -2633,6 +2695,23 @@ class flat_multimap
    inline size_type erase(const key_type& x)
       { return m_flat_tree.erase(x); }
 
+   //! <b>Requires</b>: This overload is available only if
+   //! key_compare::is_transparent exists.
+   //!
+   //! <b>Effects</b>: Erases all elements in the container with key equivalent to x.
+   //!
+   //! <b>Returns</b>: Returns the number of erased elements.
+   template <class K>
+   inline BOOST_CONTAINER_DOC1ST
+   (size_type
+      , typename dtl::enable_if_c<
+      dtl::is_transparent<key_compare>::value &&                  //transparent
+      !dtl::is_convertible<K BOOST_MOVE_I iterator>::value &&     //not convertible to iterator
+      !dtl::is_convertible<K BOOST_MOVE_I const_iterator>::value  //not convertible to const_iterator
+      BOOST_MOVE_I size_type>::type)
+      erase(const K& x)
+      { return m_flat_tree.erase(x); }
+
    //! <b>Effects</b>: Erases all the elements in the range [first, last).
    //!
    //! <b>Returns</b>: Returns last.
@@ -2977,6 +3056,10 @@ class flat_multimap
    {  x.swap(y);  }
 };
 
+#if defined(BOOST_GCC) && (BOOST_GCC >= 100000) && !defined(BOOST_CONTAINER_STD_PAIR_IS_MOVABLE)
+#pragma GCC pop_options
+#endif
+
 #ifndef BOOST_CONTAINER_NO_CXX17_CTAD
 
 template <typename InputIterator>
@@ -3052,10 +3135,10 @@ namespace boost {
 template <class Key, class T, class Compare, class AllocatorOrContainer>
 struct has_trivial_destructor_after_move< boost::container::flat_multimap<Key, T, Compare, AllocatorOrContainer> >
 {
-   typedef ::boost::container::dtl::pair<Key, T> value_t;
+   typedef typename boost::container::flat_multimap<Key, T, Compare, AllocatorOrContainer>::value_type value_t;
    typedef typename ::boost::container::dtl::container_or_allocator_rebind<AllocatorOrContainer, value_t>::type alloc_or_cont_t;
    typedef ::boost::container::dtl::flat_tree<value_t,::boost::container::dtl::select1st<Key>, Compare, alloc_or_cont_t> tree;
-   static const bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
+   BOOST_STATIC_CONSTEXPR bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
 };
 
 }  //namespace boost {
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/flat_set.hpp b/src/cxx_supportlib/vendor-modified/boost/container/flat_set.hpp
index 0c02dab77d..caffd163dd 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/flat_set.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/flat_set.hpp
@@ -1201,7 +1201,7 @@ template <class Key, class Compare, class AllocatorOrContainer>
 struct has_trivial_destructor_after_move<boost::container::flat_set<Key, Compare, AllocatorOrContainer> >
 {
    typedef ::boost::container::dtl::flat_tree<Key, ::boost::container::dtl::identity<Key>, Compare, AllocatorOrContainer> tree;
-   static const bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
+   BOOST_STATIC_CONSTEXPR bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
 };
 
 namespace container {
@@ -1932,7 +1932,7 @@ template <class Key, class Compare, class AllocatorOrContainer>
 struct has_trivial_destructor_after_move<boost::container::flat_multiset<Key, Compare, AllocatorOrContainer> >
 {
    typedef ::boost::container::dtl::flat_tree<Key, ::boost::container::dtl::identity<Key>, Compare, AllocatorOrContainer> tree;
-   static const bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
+   BOOST_STATIC_CONSTEXPR bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
 };
 
 namespace container {
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/list.hpp b/src/cxx_supportlib/vendor-modified/boost/container/list.hpp
index 04512c5246..e597c48766 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/list.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/list.hpp
@@ -43,7 +43,6 @@
 #  include <boost/move/detail/fwd_macros.hpp>
 #endif
 #include <boost/move/detail/move_helpers.hpp>
-#include <boost/move/detail/force_ptr.hpp>
 
 // intrusive
 #include <boost/intrusive/pointer_traits.hpp>
@@ -344,26 +343,13 @@ class list
                                   || allocator_traits_type::is_always_equal::value)
    {
       if (BOOST_LIKELY(this != &x)) {
-         NodeAlloc &this_alloc = this->node_alloc();
-         NodeAlloc &x_alloc    = x.node_alloc();
-         const bool propagate_alloc = allocator_traits_type::
-               propagate_on_container_move_assignment::value;
-         const bool allocators_equal = this_alloc == x_alloc; (void)allocators_equal;
-         //Resources can be transferred if both allocators are
-         //going to be equal after this function (either propagated or already equal)
-         if(propagate_alloc || allocators_equal){
-            //Destroy
-            this->clear();
-            //Move allocator if needed
-            this->AllocHolder::move_assign_alloc(x);
-            //Obtain resources
-            this->icont() = boost::move(x.icont());
-         }
-         //Else do a one by one move
-         else{
-            this->assign( boost::make_move_iterator(x.begin())
-                        , boost::make_move_iterator(x.end()));
-         }
+         //We know resources can be transferred at comiple time if both allocators are
+         //always equal or the allocator is going to be propagated
+         const bool can_steal_resources_alloc
+            =  allocator_traits_type::propagate_on_container_move_assignment::value
+            || allocator_traits_type::is_always_equal::value;
+         dtl::bool_<can_steal_resources_alloc> flag;
+         this->priv_move_assign(boost::move(x), flag);
       }
       return *this;
    }
@@ -1392,6 +1378,28 @@ class list
    #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
    private:
 
+   void priv_move_assign(BOOST_RV_REF(list) x, dtl::bool_<true> /*steal_resources*/)
+   {
+      //Destroy objects but retain memory in case x reuses it in the future
+      this->clear();
+      //Move allocator if needed
+      this->AllocHolder::move_assign_alloc(x);
+      //Obtain resources
+      this->icont() = boost::move(x.icont());
+   }
+
+   void priv_move_assign(BOOST_RV_REF(list) x, dtl::bool_<false> /*steal_resources*/)
+   {
+      //We can't guarantee a compile-time equal allocator or propagation so fallback to runtime
+      //Resources can be transferred if both allocators are equal
+      if (this->node_alloc() == x.node_alloc()) {
+         this->priv_move_assign(boost::move(x), dtl::true_());
+      }
+      else {
+         this->assign(boost::make_move_iterator(x.begin()), boost::make_move_iterator(x.end()));
+      }
+   }
+
    static bool priv_is_linked(const_iterator const position)
    {
       const_iterator cur(position);
@@ -1496,7 +1504,7 @@ struct has_trivial_destructor_after_move<boost::container::list<T, Allocator> >
 {
    typedef typename boost::container::list<T, Allocator>::allocator_type allocator_type;
    typedef typename ::boost::container::allocator_traits<allocator_type>::pointer pointer;
-   static const bool value = ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
+   BOOST_STATIC_CONSTEXPR bool value = ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
                              ::boost::has_trivial_destructor_after_move<pointer>::value;
 };
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/map.hpp b/src/cxx_supportlib/vendor-modified/boost/container/map.hpp
index 80f04aab7d..cb13c03fdb 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/map.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/map.hpp
@@ -969,6 +969,23 @@ class map
    inline size_type erase(const key_type& x)
       { return this->base_t::erase_unique(x); }
 
+   //! <b>Requires</b>: This overload is available only if
+   //! key_compare::is_transparent exists.
+   //!
+   //! <b>Effects</b>: If present, erases the element in the container with key equivalent to x.
+   //!
+   //! <b>Returns</b>: Returns the number of erased elements (0/1).
+   template <class K>
+   inline BOOST_CONTAINER_DOC1ST
+         (size_type
+         , typename dtl::enable_if_c<
+            dtl::is_transparent<key_compare>::value &&                  //transparent
+            !dtl::is_convertible<K BOOST_MOVE_I iterator>::value &&     //not convertible to iterator
+            !dtl::is_convertible<K BOOST_MOVE_I const_iterator>::value  //not convertible to const_iterator
+            BOOST_MOVE_I size_type>::type)
+      erase(const K& x)
+      { return this->base_t::erase_unique(x); }
+
    #if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
 
    //! <b>Effects</b>: Erases the element pointed to by p.
@@ -1376,7 +1393,7 @@ template <class Key, class T, class Compare, class Allocator, class Options>
 struct has_trivial_destructor_after_move<boost::container::map<Key, T, Compare, Allocator, Options> >
 {
    typedef ::boost::container::dtl::tree<std::pair<const Key, T>, int, Compare, Allocator, Options> tree;
-   static const bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
+   BOOST_STATIC_CONSTEXPR bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
 };
 
 namespace container {
@@ -2298,7 +2315,7 @@ template <class Key, class T, class Compare, class Allocator, class Options>
 struct has_trivial_destructor_after_move<boost::container::multimap<Key, T, Compare, Allocator, Options> >
 {
    typedef ::boost::container::dtl::tree<std::pair<const Key, T>, int, Compare, Allocator, Options> tree;
-   static const bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
+   BOOST_STATIC_CONSTEXPR bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
 };
 
 namespace container {
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/new_allocator.hpp b/src/cxx_supportlib/vendor-modified/boost/container/new_allocator.hpp
index b01b9ba8f2..1dadb2b7ae 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/new_allocator.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/new_allocator.hpp
@@ -33,7 +33,7 @@ namespace container {
 
 template<bool Value>
 struct new_allocator_bool
-{  static const bool value = Value;  };
+{  BOOST_STATIC_CONSTEXPR bool value = Value;  };
 
 template<class T>
 class new_allocator;
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/node_allocator.hpp b/src/cxx_supportlib/vendor-modified/boost/container/node_allocator.hpp
index d6076f4966..14c3754171 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/node_allocator.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/node_allocator.hpp
@@ -8,8 +8,8 @@
 //
 //////////////////////////////////////////////////////////////////////////////
 
-#ifndef BOOST_CONTAINER_POOLED_NODE_ALLOCATOR_HPP
-#define BOOST_CONTAINER_POOLED_NODE_ALLOCATOR_HPP
+#ifndef BOOST_CONTAINER_NODE_ALLOCATOR_HPP
+#define BOOST_CONTAINER_NODE_ALLOCATOR_HPP
 
 #ifndef BOOST_CONFIG_HPP
 #  include <boost/config.hpp>
@@ -26,6 +26,7 @@
 #include <boost/container/detail/node_pool.hpp>
 #include <boost/container/detail/mpl.hpp>
 #include <boost/container/detail/multiallocation_chain.hpp>
+#include <boost/move/detail/iterator_to_raw_pointer.hpp>
 #include <boost/container/detail/dlmalloc.hpp>
 #include <boost/container/detail/singleton.hpp>
 
@@ -62,7 +63,7 @@ class node_allocator
    typedef unsigned int allocation_type;
    typedef node_allocator<T, NodesPerBlock, Version>   self_t;
 
-   static const std::size_t nodes_per_block = NodesPerBlock;
+   BOOST_STATIC_CONSTEXPR std::size_t nodes_per_block = NodesPerBlock;
 
    BOOST_CONTAINER_STATIC_ASSERT((Version <=2));
    #endif
@@ -225,7 +226,10 @@ class node_allocator
       typedef dtl::singleton_default<shared_pool_t> singleton_t;
       typename shared_pool_t::multiallocation_chain ch;
       singleton_t::instance().allocate_nodes(num_elements, ch);
-      chain.incorporate_after(chain.before_begin(), (T*)&*ch.begin(), (T*)&*ch.last(), ch.size());
+      chain.incorporate_after(chain.before_begin()
+                             , (T*)boost::movelib::iterator_to_raw_pointer(ch.begin())
+                             , (T*)boost::movelib::iterator_to_raw_pointer(ch.last())
+                             , ch.size());
    }
 
    //!Deallocates memory previously allocated with allocate_one().
@@ -246,7 +250,10 @@ class node_allocator
       typedef dtl::shared_node_pool
          <sizeof(T), NodesPerBlock> shared_pool_t;
       typedef dtl::singleton_default<shared_pool_t> singleton_t;
-      typename shared_pool_t::multiallocation_chain ch(&*chain.begin(), &*chain.last(), chain.size());
+      typename shared_pool_t::multiallocation_chain ch
+         ( boost::movelib::iterator_to_raw_pointer(chain.begin())
+         , boost::movelib::iterator_to_raw_pointer(chain.last())
+         , chain.size());
       singleton_t::instance().deallocate_nodes(ch);
    }
 
@@ -285,8 +292,8 @@ class node_allocator
    void deallocate_many(multiallocation_chain &chain) BOOST_NOEXCEPT_OR_NOTHROW
    {
       BOOST_CONTAINER_STATIC_ASSERT(( Version > 1 ));
-      void *first = &*chain.begin();
-      void *last  = &*chain.last();
+      void *first = boost::movelib::iterator_to_raw_pointer(chain.begin());
+      void *last  = boost::movelib::iterator_to_raw_pointer(chain.last());
       size_t num  = chain.size();
       dlmalloc_memchain ch;
       BOOST_CONTAINER_MEMCHAIN_INIT_FROM(&ch, first, last, num);
@@ -337,4 +344,4 @@ class node_allocator
 
 #include <boost/container/detail/config_end.hpp>
 
-#endif   //#ifndef BOOST_CONTAINER_POOLED_NODE_ALLOCATOR_HPP
+#endif   //#ifndef BOOST_CONTAINER_NODE_ALLOCATOR_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/node_handle.hpp b/src/cxx_supportlib/vendor-modified/boost/container/node_handle.hpp
index 41bea974c3..5179022d8e 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/node_handle.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/node_handle.hpp
@@ -23,6 +23,7 @@
 #include <boost/container/detail/workaround.hpp>
 #include <boost/container/detail/placement_new.hpp>
 #include <boost/move/detail/to_raw_pointer.hpp>
+#include <boost/move/detail/launder.hpp>
 #include <boost/container/allocator_traits.hpp>
 #include <boost/container/detail/mpl.hpp>
 
@@ -146,7 +147,7 @@ class node_handle
    }
 
    void destroy_alloc() BOOST_NOEXCEPT
-   {  static_cast<nallocator_type*>((void*)m_nalloc_storage.data)->~nallocator_type();  }
+   {  move_detail::launder_cast<nallocator_type*>(&m_nalloc_storage)->~nallocator_type();  }
 
    node_pointer &get_node_pointer() BOOST_NOEXCEPT
    {  return m_ptr;  }
@@ -231,7 +232,7 @@ class node_handle
       if(was_nh_non_null){
          if(was_this_non_null){
             this->destroy_deallocate_node();
-            if(nator_traits::propagate_on_container_move_assignment::value){
+            BOOST_IF_CONSTEXPR(nator_traits::propagate_on_container_move_assignment::value){
                this->node_alloc() = ::boost::move(nh.node_alloc());
             }
          }
@@ -335,7 +336,7 @@ class node_handle
 
       if(was_nh_non_null){
          if(was_this_non_null){
-            if(nator_traits::propagate_on_container_swap::value){
+            BOOST_IF_CONSTEXPR(nator_traits::propagate_on_container_swap::value){
                ::boost::adl_move_swap(this->node_alloc(), nh.node_alloc());
             }
          }
@@ -381,7 +382,7 @@ class node_handle
    nallocator_type &node_alloc() BOOST_NOEXCEPT
    {
       BOOST_ASSERT(!empty());
-      return *static_cast<nallocator_type*>((void*)m_nalloc_storage.data);
+      return *move_detail::launder_cast<nallocator_type*>(&m_nalloc_storage);
    }
 
 
@@ -391,7 +392,7 @@ class node_handle
    const nallocator_type &node_alloc() const BOOST_NOEXCEPT
    {
       BOOST_ASSERT(!empty());
-      return *static_cast<const nallocator_type*>((const void*)m_nalloc_storage.data);
+      return *move_detail::launder_cast<const nallocator_type*>(&m_nalloc_storage);
    }
 
    //! <b>Effects</b>: x.swap(y).
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/options.hpp b/src/cxx_supportlib/vendor-modified/boost/container/options.hpp
index 48edd38197..dad41b7aef 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/options.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/options.hpp
@@ -52,8 +52,8 @@ enum tree_type_enum
 template<tree_type_enum TreeType, bool OptimizeSize>
 struct tree_opt
 {
-   static const boost::container::tree_type_enum tree_type = TreeType;
-   static const bool optimize_size = OptimizeSize;
+   BOOST_STATIC_CONSTEXPR boost::container::tree_type_enum tree_type = TreeType;
+   BOOST_STATIC_CONSTEXPR bool optimize_size = OptimizeSize;
 };
 
 typedef tree_opt<red_black_tree, true> tree_assoc_defaults;
@@ -116,10 +116,10 @@ using tree_assoc_options_t = typename boost::container::tree_assoc_options<Optio
 template<bool StoreHash, bool CacheBegin, bool LinearBuckets, bool FastmodBuckets>
 struct hash_opt
 {
-   static const bool store_hash  = StoreHash;
-   static const bool cache_begin = CacheBegin;
-   static const bool linear_buckets = LinearBuckets;
-   static const bool fastmod_buckets = FastmodBuckets;
+   BOOST_STATIC_CONSTEXPR bool store_hash  = StoreHash;
+   BOOST_STATIC_CONSTEXPR bool cache_begin = CacheBegin;
+   BOOST_STATIC_CONSTEXPR bool linear_buckets = LinearBuckets;
+   BOOST_STATIC_CONSTEXPR bool fastmod_buckets = FastmodBuckets;
 };
 
 typedef hash_opt<false, false, false, false> hash_assoc_defaults;
@@ -203,13 +203,13 @@ struct default_if_void<void, Default>
 template<std::size_t N, std::size_t DefaultN>
 struct default_if_zero
 {
-   static const std::size_t value = N;
+   BOOST_STATIC_CONSTEXPR std::size_t value = N;
 };
 
 template<std::size_t DefaultN>
 struct default_if_zero<0u, DefaultN>
 {
-   static const std::size_t value = DefaultN;
+   BOOST_STATIC_CONSTEXPR std::size_t value = DefaultN;
 };
 
 
@@ -364,7 +364,7 @@ template<class GrowthType, std::size_t InplaceAlignment>
 struct small_vector_opt
 {
    typedef GrowthType      growth_factor_type;
-   static const std::size_t inplace_alignment = InplaceAlignment;
+   BOOST_STATIC_CONSTEXPR std::size_t inplace_alignment = InplaceAlignment;
 };
 
 typedef small_vector_opt<void, 0u> small_vector_null_opt;
@@ -430,8 +430,8 @@ BOOST_INTRUSIVE_OPTION_CONSTANT(throw_on_overflow, bool, ThrowOnOverflow, throw_
 template<bool ThrowOnOverflow, std::size_t InplaceAlignment>
 struct static_vector_opt
 {
-   static const bool throw_on_overflow = ThrowOnOverflow;
-   static const std::size_t inplace_alignment = InplaceAlignment;
+   BOOST_STATIC_CONSTEXPR bool throw_on_overflow = ThrowOnOverflow;
+   BOOST_STATIC_CONSTEXPR std::size_t inplace_alignment = InplaceAlignment;
 };
 
 typedef static_vector_opt<true, 0u> static_vector_null_opt;
@@ -515,7 +515,7 @@ template<class GrowthType, class StoredSizeType, std::size_t FreeFraction>
 struct devector_opt
    : vector_opt<GrowthType, StoredSizeType>
 {
-   static const std::size_t free_fraction = FreeFraction;
+   BOOST_STATIC_CONSTEXPR std::size_t free_fraction = FreeFraction;
 };
 
 typedef devector_opt<void, void, 0u> devector_null_opt;
@@ -606,8 +606,8 @@ using devector_options_t = typename boost::container::devector_options<Options..
 template<std::size_t BlockBytes, std::size_t BlockSize>
 struct deque_opt
 {
-   static const std::size_t block_bytes = BlockBytes;
-   static const std::size_t block_size  = BlockSize;
+   BOOST_STATIC_CONSTEXPR std::size_t block_bytes = BlockBytes;
+   BOOST_STATIC_CONSTEXPR std::size_t block_size  = BlockSize;
    BOOST_CONTAINER_STATIC_ASSERT_MSG(!(block_bytes && block_size), "block_bytes and block_size can't be specified at the same time");
 };
 
@@ -617,7 +617,7 @@ typedef deque_opt<0u, 0u> deque_null_opt;
 
 //! Helper metafunction to combine options into a single type to be used
 //! by \c boost::container::deque.
-//! Supported options are: \c boost::container::block_bytes
+//! Supported options are: \c boost::container::block_bytes and \c boost::container::block_size
 #if defined(BOOST_CONTAINER_DOXYGEN_INVOKED) || defined(BOOST_CONTAINER_VARIADIC_TEMPLATES)
 template<class ...Options>
 #else
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/pmr/memory_resource.hpp b/src/cxx_supportlib/vendor-modified/boost/container/pmr/memory_resource.hpp
index 4187f05f3c..b54e75f2d6 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/pmr/memory_resource.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/pmr/memory_resource.hpp
@@ -32,7 +32,7 @@ class memory_resource
 {
    public:
    // For exposition only
-   static BOOST_CONSTEXPR_OR_CONST std::size_t max_align =
+   BOOST_STATIC_CONSTEXPR std::size_t max_align =
       boost::move_detail::alignment_of<boost::move_detail::max_align_t>::value;
 
    //! <b>Effects</b>: Destroys
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/pmr/monotonic_buffer_resource.hpp b/src/cxx_supportlib/vendor-modified/boost/container/pmr/monotonic_buffer_resource.hpp
index 6799f4f278..a52bbf8883 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/pmr/monotonic_buffer_resource.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/pmr/monotonic_buffer_resource.hpp
@@ -70,7 +70,7 @@ class BOOST_CONTAINER_DECL monotonic_buffer_resource
    //! to the upstream allocator
    //!
    //! <b>Note</b>: Non-standard extension.
-   static const std::size_t initial_next_buffer_size = 32u*sizeof(void*);
+   BOOST_STATIC_CONSTEXPR std::size_t initial_next_buffer_size = 32u*sizeof(void*);
 
    //! <b>Requires</b>: `upstream` shall be the address of a valid memory resource or `nullptr`
    //!
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/pmr/resource_adaptor.hpp b/src/cxx_supportlib/vendor-modified/boost/container/pmr/resource_adaptor.hpp
index 78f1bd3921..e53a720974 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/pmr/resource_adaptor.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/pmr/resource_adaptor.hpp
@@ -36,19 +36,19 @@ namespace pmr_dtl {
 template<class T>
 struct max_allocator_alignment
 {
-   static const std::size_t value = 1;
+   BOOST_STATIC_CONSTEXPR std::size_t value = 1;
 };
 
 template<class T>
 struct max_allocator_alignment< ::boost::container::new_allocator<T> >
 {
-   static const std::size_t value = boost::move_detail::alignment_of<boost::move_detail::max_align_t>::value;
+   BOOST_STATIC_CONSTEXPR std::size_t value = boost::move_detail::alignment_of<boost::move_detail::max_align_t>::value;
 };
 
 template<class T>
 struct max_allocator_alignment< std::allocator<T> >
 {
-   static const std::size_t value = boost::move_detail::alignment_of<boost::move_detail::max_align_t>::value;
+   BOOST_STATIC_CONSTEXPR std::size_t value = boost::move_detail::alignment_of<boost::move_detail::max_align_t>::value;
 };
 
 }  //namespace pmr_dtl
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/scoped_allocator.hpp b/src/cxx_supportlib/vendor-modified/boost/container/scoped_allocator.hpp
index a979ad658a..90e340622d 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/scoped_allocator.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/scoped_allocator.hpp
@@ -56,7 +56,7 @@ struct is_scoped_allocator_imp
    template <typename T>
    static int test(...);
 
-   static const bool value = (sizeof(yes_type) == sizeof(test<Allocator>(0)));
+   BOOST_STATIC_CONSTEXPR bool value = (sizeof(yes_type) == sizeof(test<Allocator>(0)));
 };
 
 template<class MaybeScopedAlloc, bool = is_scoped_allocator_imp<MaybeScopedAlloc>::value >
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/set.hpp b/src/cxx_supportlib/vendor-modified/boost/container/set.hpp
index 1aef8ff002..e71a1ece31 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/set.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/set.hpp
@@ -1026,7 +1026,7 @@ template <class Key, class Compare, class Allocator, class Options>
 struct has_trivial_destructor_after_move<boost::container::set<Key, Compare, Allocator, Options> >
 {
    typedef ::boost::container::dtl::tree<Key, void, Compare, Allocator, Options> tree;
-   static const bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
+   BOOST_STATIC_CONSTEXPR bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
 };
 
 namespace container {
@@ -1681,7 +1681,7 @@ template <class Key, class Compare, class Allocator, class Options>
 struct has_trivial_destructor_after_move<boost::container::multiset<Key, Compare, Allocator, Options> >
 {
    typedef ::boost::container::dtl::tree<Key, void, Compare, Allocator, Options> tree;
-   static const bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
+   BOOST_STATIC_CONSTEXPR bool value = ::boost::has_trivial_destructor_after_move<tree>::value;
 };
 
 namespace container {
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/slist.hpp b/src/cxx_supportlib/vendor-modified/boost/container/slist.hpp
index 5aa41936ec..b8853f5645 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/slist.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/slist.hpp
@@ -47,7 +47,7 @@
 #include <boost/move/detail/fwd_macros.hpp>
 #endif
 #include <boost/move/detail/move_helpers.hpp>
-#include <boost/move/detail/force_ptr.hpp>
+
 // std
 #if !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST)
 #include <initializer_list>
@@ -368,28 +368,14 @@ class slist
       BOOST_NOEXCEPT_IF(allocator_traits_type::propagate_on_container_move_assignment::value
                                   || allocator_traits_type::is_always_equal::value)
    {
-      slist & sr = x;
-      if (BOOST_LIKELY(this != &sr)) {
-         NodeAlloc &this_alloc = this->node_alloc();
-         NodeAlloc &x_alloc    = sr.node_alloc();
-         const bool propagate_alloc = allocator_traits_type::
-               propagate_on_container_move_assignment::value;
-         const bool allocators_equal = this_alloc == x_alloc; (void)allocators_equal;
-         //Resources can be transferred if both allocators are
-         //going to be equal after this function (either propagated or already equal)
-         if(propagate_alloc || allocators_equal){
-            //Destroy
-            this->clear();
-            //Move allocator if needed
-            this->AllocHolder::move_assign_alloc(sr);
-            //Obtain resources
-            this->icont() = boost::move(sr.icont());
-         }
-         //Else do a one by one move
-         else{
-            this->assign( boost::make_move_iterator(sr.begin())
-                        , boost::make_move_iterator(sr.end()));
-         }
+      if (BOOST_LIKELY(this != &x)) {
+         //We know resources can be transferred at comiple time if both allocators are
+         //always equal or the allocator is going to be propagated
+         const bool can_steal_resources_alloc
+            =  allocator_traits_type::propagate_on_container_move_assignment::value
+            || allocator_traits_type::is_always_equal::value;
+         dtl::bool_<can_steal_resources_alloc> flag;
+         this->priv_move_assign(boost::move(x), flag);
       }
       return *this;
    }
@@ -1579,6 +1565,27 @@ class slist
 
    #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
    private:
+   void priv_move_assign(BOOST_RV_REF(slist) x, dtl::bool_<true> /*steal_resources*/)
+   {
+      //Destroy objects but retain memory in case x reuses it in the future
+      this->clear();
+      //Move allocator if needed
+      this->AllocHolder::move_assign_alloc(x);
+      //Obtain resources
+      this->icont() = boost::move(x.icont());
+   }
+
+   void priv_move_assign(BOOST_RV_REF(slist) x, dtl::bool_<false> /*steal_resources*/)
+   {
+      //We can't guarantee a compile-time equal allocator or propagation so fallback to runtime
+      //Resources can be transferred if both allocators are equal
+      if (this->node_alloc() == x.node_alloc()) {
+         this->priv_move_assign(boost::move(x), dtl::true_());
+      }
+      else {
+         this->assign(boost::make_move_iterator(x.begin()), boost::make_move_iterator(x.end()));
+      }
+   }
 
    template<class U>
    void priv_push_front(BOOST_FWD_REF(U) x)
@@ -1666,7 +1673,7 @@ struct has_trivial_destructor_after_move<boost::container::slist<T, Allocator> >
 {
    typedef typename boost::container::slist<T, Allocator>::allocator_type allocator_type;
    typedef typename ::boost::container::allocator_traits<allocator_type>::pointer pointer;
-   static const bool value = ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
+   BOOST_STATIC_CONSTEXPR bool value = ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
                              ::boost::has_trivial_destructor_after_move<pointer>::value;
 };
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/small_vector.hpp b/src/cxx_supportlib/vendor-modified/boost/container/small_vector.hpp
index 28adc46b88..5882326f2c 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/small_vector.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/small_vector.hpp
@@ -39,7 +39,6 @@
 #if defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
 #include <boost/move/detail/fwd_macros.hpp>
 #endif
-#include <boost/move/detail/force_ptr.hpp>
 
 //std
 #if !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST)
@@ -284,7 +283,7 @@ class small_vector_allocator
    {  return !(l == r);   }
 
    #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
-   private:
+   public:
 
    typedef small_vector_base<value_type, allocator_type, Options>    derived_type;
    typedef typename dtl::vector_for_small_vector
@@ -305,13 +304,13 @@ struct small_vector_storage
    typedef typename dtl::aligned_storage
       <sizeof(T)*N, Alignment>::type storage_type;
    storage_type m_storage;
-   static const std::size_t sms_size = sizeof(storage_type)/sizeof(T);
+   BOOST_STATIC_CONSTEXPR std::size_t sms_size = sizeof(storage_type)/sizeof(T);
 };
 
 template<class T, std::size_t Alignment>
 struct small_vector_storage<T, 0u, Alignment>
 {
-   static const std::size_t sms_size = 0u;
+   BOOST_STATIC_CONSTEXPR std::size_t sms_size = 0u;
 };
 
 //! This class consists of common code from all small_vector<T, N> types that don't depend on the
@@ -347,9 +346,10 @@ class small_vector_base
    public:
    //Make it public as it will be inherited by small_vector and container
    //must have this public member
-   typedef typename real_allocator<T, SecAlloc>::type                     allocator_type;
-   typedef typename allocator_traits<allocator_type>::
-      template portable_rebind_alloc<void>::type                          void_allocator_t;
+   typedef typename real_allocator<T, SecAlloc>::type                     underlying_allocator_t;
+   typedef typename allocator_traits<underlying_allocator_t>::
+      template portable_rebind_alloc<void>::type                          void_underlying_allocator_t;
+   typedef small_vector_allocator<T, void_underlying_allocator_t, Options>allocator_type;
    typedef typename dtl::get_small_vector_opt<Options>::type              options_t;
    typedef typename dtl::vector_for_small_vector
       <T, SecAlloc, Options>::type                                        base_type;
@@ -357,12 +357,13 @@ class small_vector_base
    typedef typename allocator_traits<allocator_type>::const_pointer       const_pointer;
    typedef typename allocator_traits<allocator_type>::void_pointer        void_pointer;
    typedef typename allocator_traits<allocator_type>::const_void_pointer  const_void_pointer;
-   typedef small_vector_allocator<T, void_allocator_t, Options>           small_allocator_type;
+   typedef typename base_type::size_type                                  size_type;
+
 
    private: 
    BOOST_COPYABLE_AND_MOVABLE(small_vector_base)
 
-   friend class small_vector_allocator<T, void_allocator_t, Options>;
+   friend class small_vector_allocator<T, void_underlying_allocator_t, Options>;
 
    inline
    const_pointer internal_storage() const BOOST_NOEXCEPT_OR_NOTHROW
@@ -378,18 +379,26 @@ class small_vector_base
 
    public:
 
+   BOOST_CONTAINER_ATTRIBUTE_NODISCARD bool is_small() const
+   {  return this->internal_storage() == this->data();   }
+
    protected:
 
-   inline explicit small_vector_base(initial_capacity_t, std::size_t initial_capacity)
+   inline explicit small_vector_base(initial_capacity_t, size_type initial_capacity)
       : base_type(initial_capacity_t(), this->internal_storage(), initial_capacity)
    {}
 
    template<class AllocFwd>
-   inline explicit small_vector_base(initial_capacity_t, std::size_t capacity, BOOST_FWD_REF(AllocFwd) a)
+   inline explicit small_vector_base(initial_capacity_t, size_type capacity, BOOST_FWD_REF(AllocFwd) a)
       : base_type(initial_capacity_t(), this->internal_storage(), capacity, ::boost::forward<AllocFwd>(a))
    {}
 
-   inline explicit small_vector_base(maybe_initial_capacity_t, std::size_t initial_capacity, std::size_t initial_size)
+   template<class AllocFwd>
+   inline explicit small_vector_base(initial_capacity_t, size_type capacity, BOOST_FWD_REF(AllocFwd) a, small_vector_base &x)
+      : base_type(initial_capacity_t(), this->internal_storage(), capacity, ::boost::forward<AllocFwd>(a), x)
+   {}
+
+   inline explicit small_vector_base(maybe_initial_capacity_t, size_type initial_capacity, size_type initial_size)
       : base_type( maybe_initial_capacity_t()
                  , (initial_capacity >= initial_size) ? this->internal_storage() : pointer()
                  , (initial_capacity >= initial_size) ? initial_capacity : initial_size
@@ -397,7 +406,7 @@ class small_vector_base
    {}
 
    template<class AllocFwd>
-   inline explicit small_vector_base(maybe_initial_capacity_t, std::size_t initial_capacity, std::size_t initial_size, BOOST_FWD_REF(AllocFwd) a)
+   inline explicit small_vector_base(maybe_initial_capacity_t, size_type initial_capacity, size_type initial_size, BOOST_FWD_REF(AllocFwd) a)
       : base_type(maybe_initial_capacity_t()
                  , (initial_capacity >= initial_size) ? this->internal_storage() : pointer()
                  , (initial_capacity >= initial_size) ? initial_capacity : initial_size
@@ -405,11 +414,17 @@ class small_vector_base
       )
    {}
 
+   void prot_shrink_to_fit_small(const size_type small_capacity)
+   {  this->base_type::prot_shrink_to_fit_small(this->internal_storage(), small_capacity);  }
+
    using base_type::protected_set_size;
 
    //~small_vector_base(){}
    #endif   //#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
 
+   inline void prot_swap(small_vector_base& other, size_type internal_capacity_value)
+   {  this->base_type::prot_swap_small(other, internal_capacity_value);  }
+
    public:
    inline small_vector_base& operator=(BOOST_COPY_ASSIGN_REF(small_vector_base) other)
    {  return static_cast<small_vector_base&>(this->base_type::operator=(static_cast<base_type const&>(other)));  }
@@ -418,24 +433,8 @@ class small_vector_base
    {  return static_cast<small_vector_base&>(this->base_type::operator=(BOOST_MOVE_BASE(base_type, other))); }
 
    inline void swap(small_vector_base &other)
-   {  return this->base_type::swap(other);  }
+   {  return this->base_type::prot_swap_small(other, 0u);  }
 
-   #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
-   protected:
-   void move_construct_impl(base_type &x)
-   {
-      if(base_type::is_propagable_from(x.get_stored_allocator(), x.data(), this->base_type::get_stored_allocator(), true)){
-         this->steal_resources(x);
-      }
-      else{
-         const typename base_type::size_type sz = x.size();
-         ::boost::container::uninitialized_move_alloc_n_source
-            (this->base_type::get_stored_allocator(), x.begin(), sz, this->begin());
-         this->protected_set_size(sz);
-         x.clear();
-      }
-   }
-   #endif   //#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
 };
 
 #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
@@ -449,7 +448,7 @@ template<class T, std::size_t N, class Options>
 struct small_vector_storage_definer
 {
    typedef typename dtl::get_small_vector_opt<Options>::type options_t;
-   static const std::size_t final_alignment =
+   BOOST_STATIC_CONSTEXPR std::size_t final_alignment =
       options_t::inplace_alignment ? options_t::inplace_alignment : dtl::alignment_of<T>::value;
    typedef small_vector_storage<T, N, final_alignment> type;
 };
@@ -488,7 +487,7 @@ template<class T, class VoidAlloc, class Options>
 inline typename small_vector_allocator<T, VoidAlloc, Options>::const_pointer
    small_vector_allocator<T, VoidAlloc, Options>::internal_storage() const BOOST_NOEXCEPT_OR_NOTHROW
 {
-   const vector_type& v = reinterpret_cast<const vector_type&>(*this);
+   const vector_type& v = *static_cast<const vector_type*>(static_cast<const void *>(this));
    BOOST_ASSERT((std::size_t(this) % dtl::alignment_of< small_vector_storage_offset<T, allocator_type, Options> >::value) == 0);
    const char *addr = reinterpret_cast<const char*>(&v);
    typedef typename boost::intrusive::pointer_traits<pointer>::template rebind_pointer<const char>::type const_char_pointer;
@@ -501,7 +500,7 @@ template <class T, class VoidAlloc, class Options>
 inline typename small_vector_allocator<T, VoidAlloc, Options>::pointer
    small_vector_allocator<T, VoidAlloc, Options>::internal_storage() BOOST_NOEXCEPT_OR_NOTHROW
 {
-   vector_type& v = reinterpret_cast<vector_type&>(*this);
+   vector_type& v = *static_cast<vector_type*>(static_cast<void*>(this));
    BOOST_ASSERT((std::size_t(this) % dtl::alignment_of< small_vector_storage_offset<T, allocator_type, Options> >::value) == 0);
    char* addr = reinterpret_cast<char*>(&v);
    typedef typename boost::intrusive::pointer_traits<pointer>::template rebind_pointer<char>::type char_pointer;
@@ -550,7 +549,7 @@ class small_vector
    typedef typename base_type::size_type              size_type;
    typedef typename base_type::value_type             value_type;
 
-   inline static std::size_t internal_capacity()
+   inline static size_type internal_capacity()
    {  return static_capacity;  }
 
    typedef allocator_traits<typename base_type::allocator_type> allocator_traits_type;
@@ -558,7 +557,7 @@ class small_vector
    #endif   //#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
 
    //! @brief The capacity/max size of the container
-   static const size_type static_capacity = small_vector_storage_definer<T, N, Options>::type::sms_size;
+   BOOST_STATIC_CONSTEXPR size_type static_capacity = small_vector_storage_definer<T, N, Options>::type::sms_size;
 
    public:
    inline small_vector()
@@ -627,17 +626,17 @@ class small_vector
    {  this->assign(other.cbegin(), other.cend());  }
 
    inline explicit small_vector(BOOST_RV_REF(base_type) other)
-      : base_type(initial_capacity_t(), internal_capacity(), ::boost::move(other.get_stored_allocator()))
-   {  this->base_type::move_construct_impl(other);   }
+      : base_type(initial_capacity_t(), internal_capacity(), ::boost::move(other.get_stored_allocator()), other)
+   {}
 
    inline small_vector(BOOST_RV_REF(small_vector) other)
       BOOST_NOEXCEPT_IF(boost::container::dtl::is_nothrow_move_constructible<value_type>::value)
-      : base_type(initial_capacity_t(), internal_capacity(), ::boost::move(other.get_stored_allocator()))
-   {  this->base_type::move_construct_impl(other);   }
+      : base_type(initial_capacity_t(), internal_capacity(), ::boost::move(other.get_stored_allocator()), other)
+   {}
 
    inline small_vector(BOOST_RV_REF(small_vector) other, const allocator_type &a)
-      : base_type(initial_capacity_t(), internal_capacity(), a)
-   {  this->base_type::move_construct_impl(other);   }
+      : base_type(initial_capacity_t(), internal_capacity(), a, other)
+   {}
 
    #if !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST)
    inline small_vector(std::initializer_list<value_type> il, const allocator_type& a = allocator_type())
@@ -663,7 +662,10 @@ class small_vector
    {  return static_cast<small_vector&>(this->base_type::operator=(boost::move(other))); }
 
    inline void swap(small_vector &other)
-   {  return this->base_type::swap(other);  }
+   {  return this->base_type::prot_swap(other, static_capacity);  }
+
+   inline void shrink_to_fit()
+   {  this->base_type::prot_shrink_to_fit_small(this->internal_capacity());   }
 };
 
 }}
@@ -678,7 +680,7 @@ template <class T, class Allocator>
 struct has_trivial_destructor_after_move<boost::container::vector<T, Allocator> >
 {
    typedef typename ::boost::container::allocator_traits<Allocator>::pointer pointer;
-   static const bool value = ::boost::has_trivial_destructor_after_move<Allocator>::value &&
+   BOOST_STATIC_CONSTEXPR bool value = ::boost::has_trivial_destructor_after_move<Allocator>::value &&
                              ::boost::has_trivial_destructor_after_move<pointer>::value;
 };
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/stable_vector.hpp b/src/cxx_supportlib/vendor-modified/boost/container/stable_vector.hpp
index 0ab37b9d6b..e0799129c7 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/stable_vector.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/stable_vector.hpp
@@ -54,7 +54,7 @@
 #include <boost/move/utility_core.hpp>
 #include <boost/move/iterator.hpp>
 #include <boost/move/adl_move_swap.hpp>
-#include <boost/move/detail/force_ptr.hpp>
+#include <boost/move/detail/launder.hpp>
 // move/detail
 #include <boost/move/detail/move_helpers.hpp>
 #include <boost/move/detail/iterator_to_raw_pointer.hpp>
@@ -166,19 +166,19 @@ struct node
    #  endif
 
    inline T &get_data()
-   {  return *boost::move_detail::force_ptr<T*>(this->m_storage.data);   }
+   {  return *boost::move_detail::launder_cast<T*>(&this->m_storage);   }
 
    inline const T &get_data() const
-   {  return *boost::move_detail::force_ptr<const T*>(this->m_storage.data);  }
+   {  return *boost::move_detail::launder_cast<const T*>(&this->m_storage);  }
 
    inline T *get_data_ptr()
-   {  return boost::move_detail::force_ptr<T*>(this->m_storage.data);  }
+   {  return boost::move_detail::launder_cast<T*>(&this->m_storage);  }
 
    inline const T *get_data_ptr() const
-   {  return boost::move_detail::force_ptr<const T*>(this->m_storage.data);  }
+   {  return boost::move_detail::launder_cast<const T*>(&this->m_storage);  }
 
    inline ~node()
-   {  boost::move_detail::force_ptr<T*>(this->m_storage.data)->~T();   }
+   {  boost::move_detail::launder_cast<T*>(&this->m_storage)->~T();   }
 
    #if defined(BOOST_CONTAINER_DISABLE_ALIASING_WARNING)
       #pragma GCC diagnostic pop
@@ -214,7 +214,7 @@ struct index_traits
    typedef typename index_type::const_iterator        const_index_iterator;
    typedef typename index_type::size_type             size_type;
 
-   static const size_type ExtraPointers = 3;
+   BOOST_STATIC_CONSTEXPR size_type ExtraPointers = 3;
    //Stable vector stores metadata at the end of the index (node_base_ptr vector) with additional 3 pointers:
    //    back() is this->index.back() - ExtraPointers;
    //    end node index is    *(this->index.end() - 3)
@@ -598,7 +598,7 @@ class stable_vector
    #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
    private:
    BOOST_COPYABLE_AND_MOVABLE(stable_vector)
-   static const size_type ExtraPointers = index_traits_type::ExtraPointers;
+   BOOST_STATIC_CONSTEXPR size_type ExtraPointers = index_traits_type::ExtraPointers;
 
    class insert_rollback;
    friend class insert_rollback;
@@ -872,31 +872,14 @@ class stable_vector
       BOOST_NOEXCEPT_IF(allocator_traits_type::propagate_on_container_move_assignment::value
                                   || allocator_traits_type::is_always_equal::value)
    {
-      //for move constructor, no aliasing (&x != this) is assumed.
       if (BOOST_LIKELY(this != &x)) {
-         node_allocator_type &this_alloc = this->priv_node_alloc();
-         node_allocator_type &x_alloc    = x.priv_node_alloc();
-         const bool propagate_alloc = allocator_traits_type::
-               propagate_on_container_move_assignment::value;
-         dtl::bool_<propagate_alloc> flag;
-         const bool allocators_equal = this_alloc == x_alloc; (void)allocators_equal;
-         //Resources can be transferred if both allocators are
-         //going to be equal after this function (either propagated or already equal)
-         if(propagate_alloc || allocators_equal){
-            BOOST_CONTAINER_STABLE_VECTOR_CHECK_INVARIANT
-            //Destroy objects but retain memory in case x reuses it in the future
-            this->clear();
-            //Move allocator if needed
-            dtl::move_alloc(this_alloc, x_alloc, flag);
-            //Take resources
-            this->index.swap(x.index);
-            this->priv_swap_members(x);
-         }
-         //Else do a one by one move
-         else{
-            this->assign( boost::make_move_iterator(x.begin())
-                        , boost::make_move_iterator(x.end()));
-         }
+         //We know resources can be transferred at comiple time if both allocators are
+         //always equal or the allocator is going to be propagated
+         const bool can_steal_resources_alloc
+            =  allocator_traits_type::propagate_on_container_move_assignment::value
+            || allocator_traits_type::is_always_equal::value;
+         dtl::bool_<can_steal_resources_alloc> flag;
+         this->priv_move_assign(boost::move(x), flag);
       }
       return *this;
    }
@@ -1852,6 +1835,35 @@ class stable_vector
    #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
    private:
 
+   void priv_move_assign(BOOST_RV_REF(stable_vector) x, dtl::bool_<true> /*steal_resources*/)
+   {
+      //Resources can be transferred if both allocators are
+      //going to be equal after this function (either propagated or already equal)
+      BOOST_CONTAINER_STABLE_VECTOR_CHECK_INVARIANT
+      //Destroy objects but retain memory in case x reuses it in the future
+      this->clear();
+      //Move allocator if needed
+      dtl::bool_<allocator_traits_type::
+                 propagate_on_container_move_assignment::value> flag;
+      dtl::move_alloc(this->priv_node_alloc(), x.priv_node_alloc(), flag);
+
+      //Take resources
+      this->index = boost::move(x.index); //this also moves the vector's allocator if needed
+      this->priv_swap_members(x);
+   }
+
+   void priv_move_assign(BOOST_RV_REF(stable_vector) x, dtl::bool_<false> /*steal_resources*/)
+   {
+      //We can't guarantee a compile-time equal allocator or propagation so fallback to runtime
+      //Resources can be transferred if both allocators are equal
+      if (this->priv_node_alloc() == x.priv_node_alloc()) {
+         this->priv_move_assign(boost::move(x), dtl::true_());
+      }
+      else {
+         this->assign(boost::make_move_iterator(x.begin()), boost::make_move_iterator(x.end()));
+      }
+   }
+
    bool priv_in_range(const_iterator pos) const
    {
       return (this->begin() <= pos) && (pos < this->end());
@@ -2243,7 +2255,7 @@ struct has_trivial_destructor_after_move<boost::container::stable_vector<T, Allo
 {
    typedef typename boost::container::stable_vector<T, Allocator>::allocator_type allocator_type;
    typedef typename ::boost::container::allocator_traits<allocator_type>::pointer pointer;
-   static const bool value = ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
+   BOOST_STATIC_CONSTEXPR bool value = ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
                              ::boost::has_trivial_destructor_after_move<pointer>::value;
 };
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/static_vector.hpp b/src/cxx_supportlib/vendor-modified/boost/container/static_vector.hpp
index 88bf2baf74..1406fdb7de 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/static_vector.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/static_vector.hpp
@@ -22,6 +22,7 @@
 #include <boost/container/detail/config_begin.hpp>
 #include <boost/container/detail/workaround.hpp>
 #include <boost/container/detail/type_traits.hpp>
+#include <boost/move/detail/launder.hpp>
 #include <boost/container/vector.hpp>
 
 #include <cstddef>
@@ -63,12 +64,9 @@ class static_storage_allocator
    {  return *this;  }
 
    inline T* internal_storage() const BOOST_NOEXCEPT_OR_NOTHROW
-   {  return const_cast<T*>(static_cast<const T*>(static_cast<const void*>(storage.data)));  }
+   {  return move_detail::launder_cast<T*>(&storage);  }
 
-   inline T* internal_storage() BOOST_NOEXCEPT_OR_NOTHROW
-   {  return static_cast<T*>(static_cast<void*>(storage.data));  }
-
-   static const std::size_t internal_capacity = N;
+   BOOST_STATIC_CONSTEXPR std::size_t internal_capacity = N;
 
    std::size_t max_size() const
    {  return N;   }
@@ -88,7 +86,7 @@ class static_storage_allocator
 
    private:
    BOOST_CONTAINER_STATIC_ASSERT_MSG(!InplaceAlignment || (InplaceAlignment & (InplaceAlignment-1)) == 0, "Alignment option must be zero or power of two");
-   static const std::size_t final_alignment = InplaceAlignment ? InplaceAlignment : dtl::alignment_of<T>::value;
+   BOOST_STATIC_CONSTEXPR std::size_t final_alignment = InplaceAlignment ? InplaceAlignment : dtl::alignment_of<T>::value;
    typename dtl::aligned_storage<sizeof(T)*N, final_alignment>::type storage;
 };
 
@@ -190,7 +188,7 @@ class static_vector
     typedef typename base_t::const_reverse_iterator const_reverse_iterator;
 
     //! @brief The capacity/max size of the container
-    static const size_type static_capacity = Capacity;
+    BOOST_STATIC_CONSTEXPR size_type static_capacity = Capacity;
 
     //! @brief Constructs an empty static_vector.
     //!
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/string.hpp b/src/cxx_supportlib/vendor-modified/boost/container/string.hpp
index 28b4bb586b..b7eaa1adc5 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/string.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/string.hpp
@@ -43,7 +43,7 @@
 //intrusive
 #include <boost/intrusive/pointer_traits.hpp>
 #include <boost/intrusive/detail/hash_combine.hpp>
-#include <boost/move/detail/force_ptr.hpp>
+#include <boost/move/detail/launder.hpp>
 //move
 #include <boost/move/utility_core.hpp>
 #include <boost/move/adl_move_swap.hpp>
@@ -192,13 +192,13 @@ class basic_string_base
       <sizeof(long_t), dtl::alignment_of<long_t>::value>::type   long_raw_t;
 
    protected:
-   static const size_type  MinInternalBufferChars = 8;
-   static const size_type  AlignmentOfValueType =
+   BOOST_STATIC_CONSTEXPR size_type  MinInternalBufferChars = 8;
+   BOOST_STATIC_CONSTEXPR size_type  AlignmentOfValueType =
       alignment_of<value_type>::value;
-   static const size_type  ShortDataOffset = ((sizeof(short_header)-1)/AlignmentOfValueType+1)*AlignmentOfValueType;
-   static const size_type  ZeroCostInternalBufferChars =
+   BOOST_STATIC_CONSTEXPR size_type  ShortDataOffset = ((sizeof(short_header)-1)/AlignmentOfValueType+1)*AlignmentOfValueType;
+   BOOST_STATIC_CONSTEXPR size_type  ZeroCostInternalBufferChars =
       (sizeof(long_t) - ShortDataOffset)/sizeof(value_type);
-   static const size_type  UnalignedFinalInternalBufferChars =
+   BOOST_STATIC_CONSTEXPR size_type  UnalignedFinalInternalBufferChars =
       (ZeroCostInternalBufferChars > MinInternalBufferChars) ?
                 ZeroCostInternalBufferChars : MinInternalBufferChars;
 
@@ -226,7 +226,7 @@ class basic_string_base
    {
       inline void init()
       {
-         short_t &s = *::new(this->m_repr.data) short_t;
+         short_t &s = *::new(&this->m_repr) short_t;
          s.h.is_short = 1;
          s.h.length = 0;
       }
@@ -241,16 +241,16 @@ class basic_string_base
       { this->init(); }
 
       inline const short_t *pshort_repr() const
-      {  return move_detail::force_ptr<const short_t*>(m_repr.data);  }
+      {  return move_detail::launder_cast<const short_t*>(&m_repr);  }
 
       inline const long_t *plong_repr() const
-      {  return move_detail::force_ptr<const long_t*>(m_repr.data);  }
+      {  return move_detail::launder_cast<const long_t*>(&m_repr);  }
 
       inline short_t *pshort_repr()
-      {  return move_detail::force_ptr<short_t*>(m_repr.data);  }
+      {  return move_detail::launder_cast<short_t*>(&m_repr);  }
 
       inline long_t *plong_repr()
-      {  return move_detail::force_ptr<long_t*>(m_repr.data);  }
+      {  return move_detail::launder_cast<long_t*>(&m_repr);  }
 
       repr_t m_repr;
    } members_;
@@ -261,11 +261,11 @@ class basic_string_base
    inline allocator_type &alloc()
    {  return members_;  }
 
-   static const size_type InternalBufferChars = (sizeof(repr_t) - ShortDataOffset)/sizeof(value_type);
+   BOOST_STATIC_CONSTEXPR size_type InternalBufferChars = (sizeof(repr_t) - ShortDataOffset)/sizeof(value_type);
 
    private:
 
-   static const size_type MinAllocation = InternalBufferChars*2;
+   BOOST_STATIC_CONSTEXPR size_type MinAllocation = InternalBufferChars*2;
 
    protected:
    inline bool is_short() const
@@ -280,7 +280,7 @@ class basic_string_base
 
    inline short_t *construct_short()
    {
-      short_t *ps = ::new(this->members_.m_repr.data) short_t;
+      short_t *ps = ::new(&this->members_.m_repr) short_t;
       ps->h.is_short = 1;
       return ps;
    }
@@ -302,7 +302,7 @@ class basic_string_base
 
    inline long_t *construct_long()
    {
-      long_t *pl = ::new(this->members_.m_repr.data) long_t;
+      long_t *pl = ::new(&this->members_.m_repr) long_t;
       //is_short flag is written in the constructor
       return pl;
    }
@@ -469,7 +469,7 @@ class basic_string_base
    inline void priv_short_size(size_type sz)
    {
       typedef unsigned char uchar_type;
-      static const uchar_type mask = uchar_type(uchar_type(-1) >> 1U);
+      BOOST_STATIC_CONSTEXPR uchar_type mask = uchar_type(uchar_type(-1) >> 1U);
       BOOST_ASSERT( sz <= mask );
       //Make -Wconversion happy
       this->members_.pshort_repr()->h.length = uchar_type(uchar_type(sz) & mask);
@@ -477,7 +477,7 @@ class basic_string_base
 
    inline void priv_long_size(size_type sz)
    {
-      static const size_type mask = size_type(-1) >> 1U;
+      BOOST_STATIC_CONSTEXPR size_type mask = size_type(-1) >> 1U;
       BOOST_ASSERT( sz <= mask );
       //Make -Wconversion happy
       this->members_.plong_repr()->length = sz & mask;
@@ -566,7 +566,7 @@ class basic_string
    BOOST_COPYABLE_AND_MOVABLE(basic_string)
    typedef dtl::basic_string_base<typename real_allocator<CharT, Allocator>::type> base_t;
    typedef typename base_t::allocator_traits_type allocator_traits_type;
-   static const typename base_t::size_type InternalBufferChars = base_t::InternalBufferChars;
+   BOOST_STATIC_CONSTEXPR typename base_t::size_type InternalBufferChars = base_t::InternalBufferChars;
 
    protected:
    // Allocator helper class to use a char_traits as a function object.
@@ -624,7 +624,7 @@ class basic_string
    typedef BOOST_CONTAINER_IMPDEF(const_pointer)                                       const_iterator;
    typedef BOOST_CONTAINER_IMPDEF(boost::container::reverse_iterator<iterator>)        reverse_iterator;
    typedef BOOST_CONTAINER_IMPDEF(boost::container::reverse_iterator<const_iterator>)  const_reverse_iterator;
-   static const size_type npos = size_type(-1);
+   BOOST_STATIC_CONSTEXPR size_type npos = size_type(-1);
 
    #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
    private:
@@ -913,26 +913,13 @@ class basic_string
                                   || allocator_traits_type::is_always_equal::value)
    {
       if (BOOST_LIKELY(this != &x)) {
-         allocator_type &this_alloc = this->alloc();
-         allocator_type &x_alloc    = x.alloc();
-         const bool propagate_alloc = allocator_traits_type::
-               propagate_on_container_move_assignment::value;
-         dtl::bool_<propagate_alloc> flag;
-         const bool allocators_equal = this_alloc == x_alloc; (void)allocators_equal;
-         //Resources can be transferred if both allocators are
-         //going to be equal after this function (either propagated or already equal)
-         if(propagate_alloc || allocators_equal){
-            //Destroy objects but retain memory in case x reuses it in the future
-            this->clear();
-            //Move allocator if needed
-            dtl::move_alloc(this_alloc, x_alloc, flag);
-            //Nothrow swap
-            this->swap_data(x);
-         }
-         //Else do a one by one move
-         else{
-            this->assign( x.begin(), x.end());
-         }
+         //We know resources can be transferred at comiple time if both allocators are
+         //always equal or the allocator is going to be propagated
+         const bool can_steal_resources_alloc
+            =  allocator_traits_type::propagate_on_container_move_assignment::value
+            || allocator_traits_type::is_always_equal::value;
+         dtl::bool_<can_steal_resources_alloc> flag;
+         this->priv_move_assign(boost::move(x), flag);
       }
       return *this;
    }
@@ -2908,6 +2895,30 @@ class basic_string
 
    #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
    private:
+   void priv_move_assign(BOOST_RV_REF(basic_string) x, dtl::bool_<true> /*steal_resources*/)
+   {
+      //Destroy objects but retain memory in case x reuses it in the future
+      this->clear();
+      //Move allocator if needed
+      dtl::bool_<allocator_traits_type::
+         propagate_on_container_move_assignment::value> flag;
+      dtl::move_alloc(this->alloc(), x.alloc(), flag);
+      //Nothrow swap
+      this->swap_data(x);
+   }
+
+   void priv_move_assign(BOOST_RV_REF(basic_string) x, dtl::bool_<false> /*steal_resources*/)
+   {
+      //We can't guarantee a compile-time equal allocator or propagation so fallback to runtime
+      //Resources can be transferred if both allocators are equal
+      if (this->alloc() == x.alloc()) {
+         this->priv_move_assign(boost::move(x), dtl::true_());
+      }
+      else {
+         this->assign(x.begin(), x.end());
+      }
+   }
+
    bool priv_reserve_no_null_end(size_type res_arg)
    {
       if (res_arg > this->max_size()){
@@ -3074,20 +3085,16 @@ wstring;
 
 #else
 
-template <class CharT, class Traits, class Allocator>
-const typename basic_string<CharT,Traits,Allocator>::size_type
-   basic_string<CharT,Traits,Allocator>::npos;
-
 template<class S>
 struct is_string
 {
-   static const bool value = false;
+   BOOST_STATIC_CONSTEXPR bool value = false;
 };
 
 template<class C, class T, class A>
 struct is_string< basic_string<C, T, A> >
 {
-   static const bool value = true;
+   BOOST_STATIC_CONSTEXPR bool value = true;
 };
 
 #endif
@@ -3572,8 +3579,9 @@ struct has_trivial_destructor_after_move<boost::container::basic_string<C, T, Al
 {
    typedef typename boost::container::basic_string<C, T, Allocator>::allocator_type allocator_type;
    typedef typename ::boost::container::allocator_traits<allocator_type>::pointer pointer;
-   static const bool value = ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
-                             ::boost::has_trivial_destructor_after_move<pointer>::value;
+   BOOST_STATIC_CONSTEXPR bool value =
+      ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
+      ::boost::has_trivial_destructor_after_move<pointer>::value;
 };
 
 }
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/uses_allocator.hpp b/src/cxx_supportlib/vendor-modified/boost/container/uses_allocator.hpp
index e0e3518081..11915e645d 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/uses_allocator.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/uses_allocator.hpp
@@ -58,7 +58,7 @@ namespace container {
 //! to detect if a type should be constructed with suffix or prefix allocator arguments.
 template <class T>
 struct constructible_with_allocator_suffix
-{  static const bool value = false; };
+{  BOOST_STATIC_CONSTEXPR bool value = false; };
 
 //! <b>Remark</b>: if a specialization constructible_with_allocator_prefix<X>::value is true, indicates that T may be constructed
 //! with allocator_arg and T::allocator_type as its first two constructor arguments.
@@ -108,7 +108,7 @@ struct constructible_with_allocator_suffix
 //! to detect if a type should be constructed with suffix or prefix allocator arguments.
 template <class T>
 struct constructible_with_allocator_prefix
-{  static const bool value = false; };
+{  BOOST_STATIC_CONSTEXPR bool value = false; };
 
 #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
 
@@ -142,7 +142,7 @@ struct uses_allocator_imp
    static Allocator alloc;  // Declared but not defined
 
    public:
-   static const bool value = sizeof(test<T>(alloc)) == sizeof(yes_type);
+   BOOST_STATIC_CONSTEXPR bool value = sizeof(test<T>(alloc)) == sizeof(yes_type);
 };
 
 }  //namespace dtl {
diff --git a/src/cxx_supportlib/vendor-modified/boost/container/vector.hpp b/src/cxx_supportlib/vendor-modified/boost/container/vector.hpp
index 503a80ba3d..091417620f 100644
--- a/src/cxx_supportlib/vendor-modified/boost/container/vector.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/container/vector.hpp
@@ -51,6 +51,7 @@
 #include <boost/move/iterator.hpp>
 #include <boost/move/traits.hpp>
 #include <boost/move/utility_core.hpp>
+#include <boost/move/detail/launder.hpp>
 // move/detail
 #if defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
 #include <boost/move/detail/fwd_macros.hpp>
@@ -268,15 +269,15 @@ inline Pointer &get_ptr(vec_iterator<Pointer, IsConst> &it) BOOST_NOEXCEPT_OR_NO
 struct initial_capacity_t {};
 
 struct vector_uninitialized_size_t {};
-static const vector_uninitialized_size_t vector_uninitialized_size = vector_uninitialized_size_t();
+BOOST_CONTAINER_CONSTANT_VAR vector_uninitialized_size_t vector_uninitialized_size = vector_uninitialized_size_t();
 
 struct maybe_initial_capacity_t {};
 
 template <class T>
 struct vector_value_traits_base
 {
-   static const bool trivial_dctr = dtl::is_trivially_destructible<T>::value;
-   static const bool trivial_dctr_after_move = has_trivial_destructor_after_move<T>::value;
+   BOOST_STATIC_CONSTEXPR bool trivial_dctr = dtl::is_trivially_destructible<T>::value;
+   BOOST_STATIC_CONSTEXPR bool trivial_dctr_after_move = has_trivial_destructor_after_move<T>::value;
 };
 
 template <class Allocator>
@@ -351,23 +352,23 @@ struct vector_alloc_holder
 
    public:
 
-   inline
-      static bool is_propagable_from(const allocator_type &from_alloc, pointer p, const allocator_type &to_alloc, bool const propagate_allocator)
+   template <bool PropagateAllocator>
+   inline static bool is_propagable_from(const allocator_type &from_alloc, pointer p, const allocator_type &to_alloc)
    {
-      (void)propagate_allocator; (void)p; (void)to_alloc; (void)from_alloc;
+      (void)p; (void)to_alloc; (void)from_alloc;
       const bool all_storage_propagable = !allocator_traits_type::is_partially_propagable::value ||
                                           !allocator_traits_type::storage_is_unpropagable(from_alloc, p);
       return all_storage_propagable &&
-         (propagate_allocator || allocator_traits_type::is_always_equal::value || allocator_traits_type::equal(from_alloc, to_alloc));
+         (PropagateAllocator || allocator_traits_type::is_always_equal::value || allocator_traits_type::equal(from_alloc, to_alloc));
    }
 
-   inline
-      static bool are_swap_propagable(const allocator_type &l_a, pointer l_p, const allocator_type &r_a, pointer r_p, bool const propagate_allocator)
+   template <bool PropagateAllocator>
+   inline static bool are_swap_propagable(const allocator_type &l_a, pointer l_p, const allocator_type &r_a, pointer r_p)
    {
-      (void)propagate_allocator; (void)l_p; (void)r_p; (void)l_a; (void)r_a;
+      (void)l_p; (void)r_p; (void)l_a; (void)r_a;
       const bool all_storage_propagable = !allocator_traits_type::is_partially_propagable::value || 
               !(allocator_traits_type::storage_is_unpropagable(l_a, l_p) || allocator_traits_type::storage_is_unpropagable(r_a, r_p));
-      return all_storage_propagable && (propagate_allocator || allocator_traits_type::equal(l_a, r_a));
+      return all_storage_propagable && (PropagateAllocator || allocator_traits_type::is_always_equal::value || allocator_traits_type::equal(l_a, r_a));
    }
 
    //Constructor, does not throw
@@ -545,7 +546,7 @@ struct vector_alloc_holder
    inline const allocator_type &alloc() const BOOST_NOEXCEPT_OR_NOTHROW
    {  return *this;  }
 
-   inline const pointer   &start() const     BOOST_NOEXCEPT_OR_NOTHROW
+   inline pointer   start() const     BOOST_NOEXCEPT_OR_NOTHROW
       {  return m_start;  }
    inline       size_type capacity() const     BOOST_NOEXCEPT_OR_NOTHROW
       {  return m_capacity;  }
@@ -837,14 +838,14 @@ class vector
 
 
    protected:
-   inline
-      static bool is_propagable_from(const allocator_type &from_alloc, pointer p, const allocator_type &to_alloc, bool const propagate_allocator)
-   {  return alloc_holder_t::is_propagable_from(from_alloc, p, to_alloc, propagate_allocator);  }
+   template <bool PropagateAllocator>
+   inline static bool is_propagable_from(const allocator_type &from_alloc, pointer p, const allocator_type &to_alloc)
+   {  return alloc_holder_t::template is_propagable_from<PropagateAllocator>(from_alloc, p, to_alloc);  }
 
-   inline
-      static bool are_swap_propagable( const allocator_type &l_a, pointer l_p
-                                     , const allocator_type &r_a, pointer r_p, bool const propagate_allocator)
-   {  return alloc_holder_t::are_swap_propagable(l_a, l_p, r_a, r_p, propagate_allocator);  }
+   template <bool PropagateAllocator>
+   inline static bool are_swap_propagable( const allocator_type &l_a, pointer l_p
+                                         , const allocator_type &r_a, pointer r_p)
+   {  return alloc_holder_t::template are_swap_propagable<PropagateAllocator>(l_a, l_p, r_a, r_p);  }
 
    #endif   //#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
    #ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
@@ -866,6 +867,25 @@ class vector
       : m_holder(initial_capacity_t(), initial_memory, cap, ::boost::forward<AllocFwd>(a))
    {}
 
+   template<class AllocFwd>
+   inline vector(initial_capacity_t, pointer initial_memory, size_type cap, BOOST_FWD_REF(AllocFwd) a, vector &x)
+      : m_holder(initial_capacity_t(), initial_memory, cap, ::boost::forward<AllocFwd>(a))
+   {
+      allocator_type &this_al = this->get_stored_allocator();
+      if (this->template is_propagable_from<true>(x.get_stored_allocator(), x.data(), this_al)) {
+         this->steal_resources(x);
+      }
+      else {
+         const size_type sz = x.size();
+         ::boost::container::uninitialized_move_alloc_n_source
+            ( this_al, x.priv_raw_begin(), sz
+            //Use launder to stop false positives from -Warray-bounds
+            , boost::move_detail::launder(this->priv_raw_begin()));
+         this->protected_set_size(sz);
+         x.clear();
+      }
+   }
+
    inline vector(initial_capacity_t, pointer initial_memory, size_type cap)
       : m_holder(initial_capacity_t(), initial_memory, cap)
    {}
@@ -1163,11 +1183,11 @@ class vector
    vector(BOOST_RV_REF(vector) x, const allocator_type &a)
       :  m_holder( vector_uninitialized_size, a
                  //In this allocator move constructor the allocator won't be propagated --v
-                 , is_propagable_from(x.get_stored_allocator(), x.m_holder.start(), a, false) ? 0 : x.size()
+                 , is_propagable_from<false>(x.get_stored_allocator(), x.m_holder.start(), a) ? 0 : x.size()
                  )
    {
       //In this allocator move constructor the allocator won't be propagated ---v
-      if(is_propagable_from(x.get_stored_allocator(), x.m_holder.start(), a, false)){
+      if(is_propagable_from<false>(x.get_stored_allocator(), x.m_holder.start(), a)){
          this->m_holder.steal_resources(x.m_holder);
       }
       else{
@@ -2228,7 +2248,7 @@ class vector
 
    #endif   //#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
 
-   //! <b>Effects</b>: Erases all the elements of the vector.
+   //! <b>Effects</b>: Erases all the elements of the vector. Leaves the capacity() of the vector unchanged.
    //!
    //! <b>Throws</b>: Nothing.
    //!
@@ -2531,6 +2551,38 @@ class vector
       x.clear();
    }
 
+   template<class OtherA>
+   void priv_move_assign_steal_or_assign(BOOST_RV_REF_BEG vector<T, OtherA, Options> BOOST_RV_REF_END x, dtl::true_type /*data_can_be_always_stolen*/)
+   {
+      this->clear();
+      if (BOOST_LIKELY(!!this->m_holder.m_start))
+         this->m_holder.deallocate(this->m_holder.m_start, this->m_holder.m_capacity);
+      this->m_holder.steal_resources(x.m_holder);
+   }
+
+   template<class OtherA>
+   void priv_move_assign_steal_or_assign(BOOST_RV_REF_BEG vector<T, OtherA, Options> BOOST_RV_REF_END x, dtl::false_type /*data_can_be_always_stolen*/)
+   {
+      const bool propagate_alloc = allocator_traits_type::propagate_on_container_move_assignment::value;
+      allocator_type& this_alloc = this->m_holder.alloc();
+      allocator_type& x_alloc = x.m_holder.alloc();
+
+      //In this allocator move constructor the allocator might will be propagated, but to support small_vector-like
+      //types, we need to check the currently owned buffers to know if they are propagable.
+      const bool is_buffer_propagable_from_x = is_propagable_from<propagate_alloc>(x_alloc, x.m_holder.start(), this_alloc);
+
+      if (is_buffer_propagable_from_x) {
+         this->priv_move_assign_steal_or_assign(boost::move(x), dtl::true_type());
+      }
+      //Else do a one by one move. Also, clear the source as users find confusing
+      //elements are still alive in the source container.
+      else {
+         this->assign( boost::make_move_iterator(boost::movelib::iterator_to_raw_pointer(x.begin()))
+                     , boost::make_move_iterator(boost::movelib::iterator_to_raw_pointer(x.end()))   );
+         x.clear();
+      }
+   }
+
    template<class OtherA>
    void priv_move_assign(BOOST_RV_REF_BEG vector<T, OtherA, Options> BOOST_RV_REF_END x
       , typename dtl::disable_if_or
@@ -2542,30 +2594,16 @@ class vector
       //for move assignment, no aliasing (&x != this) is assumed.
       //x.size() == 0 is allowed for buggy std libraries.
       BOOST_ASSERT(this != &x || x.size() == 0);
-      allocator_type &this_alloc = this->m_holder.alloc();
-      allocator_type &x_alloc    = x.m_holder.alloc();
+      const bool alloc_is_always_equal = allocator_traits_type::is_always_equal::value;
       const bool propagate_alloc = allocator_traits_type::propagate_on_container_move_assignment::value;
+      const bool partially_propagable_alloc = allocator_traits_type::is_partially_propagable::value;
+      const bool data_can_be_always_be_stolen = alloc_is_always_equal || (propagate_alloc && !partially_propagable_alloc);
 
-      //In this allocator move constructor the allocator maybe will be propagated -----------------------v
-      const bool is_propagable_from_x = is_propagable_from(x_alloc, x.m_holder.start(), this_alloc, propagate_alloc);
+      this->priv_move_assign_steal_or_assign(boost::move(x), dtl::bool_<data_can_be_always_be_stolen>());
 
-      //Resources can be transferred if both allocators are
-      //going to be equal after this function (either propagated or already equal)
-      if(is_propagable_from_x){
-         this->clear();
-         if(BOOST_LIKELY(!!this->m_holder.m_start))
-            this->m_holder.deallocate(this->m_holder.m_start, this->m_holder.m_capacity);
-         this->m_holder.steal_resources(x.m_holder);
-      }
-      //Else do a one by one move. Also, clear the source as users find confusing
-      //elements are still alive in the source container.
-      else{
-         this->assign( boost::make_move_iterator(boost::movelib::iterator_to_raw_pointer(x.begin()))
-                     , boost::make_move_iterator(boost::movelib::iterator_to_raw_pointer(x.end()  ))
-                     );
-         x.clear();
-      }
       //Move allocator if needed
+      allocator_type& this_alloc = this->m_holder.alloc();
+      allocator_type& x_alloc    = x.m_holder.alloc();
       dtl::move_alloc(this_alloc, x_alloc, dtl::bool_<propagate_alloc>());
    }
 
@@ -2613,46 +2651,115 @@ class vector
    template<class Vector>  //Template it to avoid it in explicit instantiations
    void priv_swap(Vector &x, dtl::false_type)  //version_N
    {
-      const bool propagate_alloc = allocator_traits_type::propagate_on_container_swap::value;
+      BOOST_ASSERT(allocator_traits_type::propagate_on_container_swap::value ||
+                   allocator_traits_type::is_always_equal::value ||
+                   this->get_stored_allocator() == x.get_stored_allocator());
+
+      if (BOOST_UNLIKELY(&x == this)) {
+         return;
+      }
+
+      //Just swap internals
+      this->m_holder.swap_resources(x.m_holder);
+      //And now swap the allocator
+      dtl::bool_<allocator_traits_type::propagate_on_container_swap::value> flag;
+      dtl::swap_alloc(this->m_holder.alloc(), x.m_holder.alloc(), flag);
+   }
+
+   protected:
+   template<class Vector>  //Template it to avoid it in explicit instantiations
+   void prot_swap_small(Vector &x, std::size_t internal_capacity)  //version_N
+   {
       if (BOOST_UNLIKELY(&x == this)){
          return;
       }
-      else if(are_swap_propagable( this->get_stored_allocator(), this->m_holder.start()
-                                 , x.get_stored_allocator(), x.m_holder.start(), propagate_alloc)){
-         //Just swap internals
-         this->m_holder.swap_resources(x.m_holder);
+
+      const bool propagate_alloc = allocator_traits_type::propagate_on_container_swap::value;
+      if(are_swap_propagable<propagate_alloc>
+         ( this->get_stored_allocator(), this->m_holder.start(), x.get_stored_allocator(), x.m_holder.start())){
+         this->priv_swap(x, dtl::false_());
+         return;
       }
-      else{
-         //Else swap element by element...
+
+      allocator_type &th_al = this->get_stored_allocator();
+      allocator_type &ot_al = x.get_stored_allocator();
+
+      const bool is_this_data_propagable = is_propagable_from<propagate_alloc>(th_al, this->data(), ot_al);
+      const bool is_that_data_propagable = is_propagable_from<propagate_alloc>(ot_al, x.data(), th_al);
+
+      if(internal_capacity && (is_this_data_propagable || is_that_data_propagable)) {
+         //steal memory from src to dst, but move elements from dst to src
+         vector& extmem = is_this_data_propagable ? *this : x;
+         vector& intmem = is_this_data_propagable ? x : *this;
+
+         //Reset extmem to the internal storage and backup data
+         pointer const orig_extdata = extmem.data();
+         const size_type orig_extmem_size = extmem.size();
+         const size_type orig_extmem_cap = extmem.capacity();
+
+         //New safe state for extmem -> empty, internal storage
+         extmem.m_holder.m_start = extmem.get_stored_allocator().internal_storage();
+         extmem.m_holder.set_stored_size(0u);
+         extmem.m_holder.set_stored_capacity(internal_capacity);
+
+         {
+            //Deallocate on exception
+            typename value_traits::ArrayDeallocator new_buffer_deallocator(orig_extdata, extmem.get_stored_allocator(), orig_extmem_cap);
+            typename value_traits::ArrayDestructor  new_values_destroyer(orig_extdata, extmem.get_stored_allocator(), orig_extmem_size);
+
+            //Move internal memory data to the internal memory data of the target, this can throw
+            BOOST_ASSERT(extmem.capacity() >= intmem.size());
+            ::boost::container::uninitialized_move_alloc_n
+               (intmem.get_stored_allocator(), this->priv_raw_begin(), intmem.size(), extmem.priv_raw_begin());
+
+            //Exception not thrown, commit new state
+            extmem.m_holder.set_stored_size(intmem.size());
+            //Throwing part passed, disable rollback
+            new_buffer_deallocator.release();
+            new_values_destroyer.release();
+         }
+
+         //Destroy moved elements from intmem
+         boost::container::destroy_alloc_n
+            ( intmem.get_stored_allocator(), this->priv_raw_begin()
+            , intmem.size());
+
+         //Adopt dynamic buffer
+         intmem.m_holder.m_start = orig_extdata;
+         intmem.m_holder.set_stored_size(orig_extmem_size);
+         intmem.m_holder.set_stored_capacity(orig_extmem_cap);
+
+         //And now swap the allocator
+         dtl::swap_alloc(this->m_holder.alloc(), x.m_holder.alloc(), dtl::bool_<propagate_alloc>());
+      }
+      else {   //swap element by element and insert rest
          bool const t_smaller = this->size() < x.size();
          vector &sml = t_smaller ? *this : x;
          vector &big = t_smaller ? x : *this;
 
-         //For empty containers, maybe storage can be moved from the other (just like in the move constructor)         
-         if(sml.empty() && is_propagable_from(big.get_stored_allocator(), big.data(), sml.get_allocator(), propagate_alloc)){
-            if(BOOST_LIKELY(0u != sml.capacity()))
-               sml.m_holder.deallocate(sml.m_holder.m_start, sml.m_holder.m_capacity);
-            sml.steal_resources(big);
-         }
-         else {
-            //Else swap element by element...
-            size_type const common_elements = sml.size();
-            for(size_type i = 0; i != common_elements; ++i){
-               boost::adl_move_swap(sml[i], big[i]);
-            }
-            //... and move-insert the remaining range
-            sml.insert( sml.cend()
-                      , boost::make_move_iterator(boost::movelib::iterator_to_raw_pointer(big.nth(common_elements)))
-                      , boost::make_move_iterator(boost::movelib::iterator_to_raw_pointer(big.end()))
-                      );
-            //Destroy remaining elements
-            big.erase(big.nth(common_elements), big.cend());
+         //swap element by element until common size
+         size_type const common_elements = sml.size();
+         for(size_type i = 0; i != common_elements; ++i){
+            boost::adl_move_swap(sml[i], big[i]);
          }
+
+         //And now swap the allocator to be able to construct new elements in sml with the proper allocator
+         dtl::swap_alloc(this->m_holder.alloc(), x.m_holder.alloc(), dtl::bool_<propagate_alloc>());
+
+         //move-insert the remaining range
+         T *const raw_big_nth = boost::movelib::iterator_to_raw_pointer(big.nth(common_elements));
+         sml.insert(sml.cend()
+            , boost::make_move_iterator(raw_big_nth)
+            , boost::make_move_iterator(boost::movelib::iterator_to_raw_pointer(big.end())));
+
+         //Destroy remaining, moved, elements with their original allocator
+         boost::container::destroy_alloc_n
+            ( sml.get_stored_allocator(), raw_big_nth
+            , std::size_t(big.m_holder.m_size - common_elements));
+         big.m_holder.set_stored_size(common_elements);
       }
-      //And now swap the allocator
-      dtl::swap_alloc(this->m_holder.alloc(), x.m_holder.alloc(), dtl::bool_<propagate_alloc>());
    }
-
+   private:
    inline void priv_move_to_new_buffer(size_type, version_0)
    {  alloc_holder_t::on_capacity_overflow();  }
 
@@ -2762,6 +2869,41 @@ class vector
    inline dtl::insert_value_initialized_n_proxy<allocator_type> priv_resize_proxy(value_init_t)
    {  return dtl::insert_value_initialized_n_proxy<allocator_type>(); }
 
+   protected:
+   void prot_shrink_to_fit_small(pointer const small_buffer, const size_type small_capacity)
+   {
+      const size_type cp = this->m_holder.capacity();
+      if (cp && this->m_holder.m_start != small_buffer) {   //Do something only if a dynamic buffer is used
+         const size_type sz = this->size();
+         if (!sz) {
+            if (BOOST_LIKELY(!!this->m_holder.m_start))
+               this->m_holder.deallocate(this->m_holder.m_start, cp);
+            this->m_holder.m_start = small_buffer;
+            this->m_holder.set_stored_capacity(small_capacity);
+         }
+         else if(sz <= small_capacity) {
+            T *const oldbuf = boost::movelib::to_raw_pointer(this->m_holder.m_start);
+            ::boost::container::uninitialized_move_alloc_n
+               ( this->get_stored_allocator()
+               , oldbuf
+               , sz
+               , boost::movelib::to_raw_pointer(small_buffer)
+               );
+            boost::container::destroy_alloc_n(this->get_stored_allocator(), oldbuf, sz);
+
+            if (BOOST_LIKELY(!!this->m_holder.m_start))
+               this->m_holder.deallocate(this->m_holder.m_start, cp);
+
+            this->m_holder.m_start = small_buffer;
+            this->m_holder.set_stored_capacity(small_capacity);
+         }
+         else if (sz < cp) {
+            this->priv_move_to_new_buffer(sz, alloc_version());
+         }
+      }
+   }
+
+   private:
    inline void priv_shrink_to_fit(version_0) BOOST_NOEXCEPT_OR_NOTHROW
    {}
 
@@ -2807,12 +2949,19 @@ class vector
       }
    }
 
+   #ifdef _MSC_VER
+   #pragma warning (push)
+   #pragma warning(disable: 4702)   //Disable unreachable code warning
+   #endif
    template <class InsertionProxy>
    inline iterator priv_insert_forward_range_no_capacity
       (T * const, const size_type, const InsertionProxy , version_0)
    {
       return alloc_holder_t::on_capacity_overflow(), iterator();
    }
+   #ifdef _MSC_VER
+   #pragma warning (pop)
+   #endif
 
    template <class InsertionProxy>
    BOOST_CONTAINER_NOINLINE iterator priv_insert_forward_range_no_capacity
@@ -3161,8 +3310,8 @@ struct has_trivial_destructor_after_move<boost::container::vector<T, Allocator,
 {
    typedef typename boost::container::vector<T, Allocator, Options>::allocator_type allocator_type;
    typedef typename ::boost::container::allocator_traits<allocator_type>::pointer pointer;
-   static const bool value = ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
-                             ::boost::has_trivial_destructor_after_move<pointer>::value;
+   BOOST_STATIC_CONSTEXPR bool value = ::boost::has_trivial_destructor_after_move<allocator_type>::value &&
+                                                ::boost::has_trivial_destructor_after_move<pointer>::value;
 };
 
 }
diff --git a/src/cxx_supportlib/vendor-modified/boost/core/detail/minstd_rand.hpp b/src/cxx_supportlib/vendor-modified/boost/core/detail/minstd_rand.hpp
new file mode 100644
index 0000000000..bedafb2887
--- /dev/null
+++ b/src/cxx_supportlib/vendor-modified/boost/core/detail/minstd_rand.hpp
@@ -0,0 +1,58 @@
+#ifndef BOOST_CORE_DETAIL_MINSTD_RAND_HPP_INCLUDED
+#define BOOST_CORE_DETAIL_MINSTD_RAND_HPP_INCLUDED
+
+// Copyright 2017 Peter Dimov
+//
+// Distributed under the Boost Software License, Version 1.0.
+//
+// See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt
+//
+// An implementation of minstd_rand that does not require
+// the Random library
+
+#include <boost/cstdint.hpp>
+
+namespace boost
+{
+namespace detail
+{
+
+class minstd_rand
+{
+private:
+
+    boost::uint_least32_t x_;
+
+    enum { a = 48271, m = 2147483647 };
+
+public:
+
+    minstd_rand(): x_( 1 )
+    {
+    }
+
+    explicit minstd_rand( boost::uint_least32_t x ): x_( x % m )
+    {
+        if( x_ == 0 )
+        {
+            x_ = 1;
+        }
+    }
+
+    boost::uint_least32_t operator()()
+    {
+        boost::uint_least64_t y = x_;
+
+        y = ( a * y ) % m;
+
+        x_ = static_cast<boost::uint_least32_t>( y );
+
+        return x_;
+    }
+};
+
+} // namespace detail
+} // namespace boost
+
+#endif // #ifndef BOOST_CORE_DETAIL_MINSTD_RAND_HPP_INCLUDED
diff --git a/src/cxx_supportlib/vendor-modified/boost/core/detail/string_view.hpp b/src/cxx_supportlib/vendor-modified/boost/core/detail/string_view.hpp
index 223654545e..5cce6f6cec 100644
--- a/src/cxx_supportlib/vendor-modified/boost/core/detail/string_view.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/core/detail/string_view.hpp
@@ -74,7 +74,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_first_of( Ch const* p_
 
     for( std::size_t j = 0; j < n; ++j )
     {
-        UCh ch = s[ j ];
+        UCh ch = static_cast<UCh>( s[ j ] );
 
         if( ch >= 0 && ch < 256 )
         {
@@ -91,7 +91,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_first_of( Ch const* p_
     {
         for( std::size_t i = pos; i < n_; ++i )
         {
-            UCh ch = p_[ i ];
+            UCh ch = static_cast<UCh>( p_[ i ] );
             if( ch >= 0 && ch < 256 && table[ ch ] ) return i;
         }
     }
@@ -129,7 +129,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_last_of( Ch const* p_,
 
     for( std::size_t j = 0; j < n; ++j )
     {
-        UCh ch = s[ j ];
+        UCh ch = static_cast<UCh>( s[ j ] );
 
         if( ch >= 0 && ch < 256 )
         {
@@ -150,7 +150,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_last_of( Ch const* p_,
     {
         do
         {
-            UCh ch = p_[ i ];
+            UCh ch = static_cast<UCh>( p_[ i ] );
 
             if( ch >= 0 && ch < 256 && table[ ch ] ) return i;
 
@@ -199,7 +199,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_first_not_of( Ch const
 
     for( std::size_t j = 0; j < n; ++j )
     {
-        UCh ch = s[ j ];
+        UCh ch = static_cast<UCh>( s[ j ] );
 
         if( ch >= 0 && ch < 256 )
         {
@@ -216,7 +216,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_first_not_of( Ch const
     {
         for( std::size_t i = pos; i < n_; ++i )
         {
-            UCh ch = p_[ i ];
+            UCh ch = static_cast<UCh>( p_[ i ] );
             if( !( ch >= 0 && ch < 256 && table[ ch ] ) ) return i;
         }
     }
@@ -262,7 +262,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_last_not_of( Ch const*
 
     for( std::size_t j = 0; j < n; ++j )
     {
-        UCh ch = s[ j ];
+        UCh ch = static_cast<UCh>( s[ j ] );
 
         if( ch >= 0 && ch < 256 )
         {
@@ -283,7 +283,7 @@ template<class Ch> BOOST_CXX14_CONSTEXPR std::size_t find_last_not_of( Ch const*
     {
         do
         {
-            UCh ch = p_[ i ];
+            UCh ch = static_cast<UCh>( p_[ i ] );
 
             if( !( ch >= 0 && ch < 256 && table[ ch ] ) ) return i;
 
@@ -381,7 +381,7 @@ template<class Ch> class basic_string_view
     }
 
     template<class End> BOOST_CXX14_CONSTEXPR basic_string_view( Ch const* first, End last,
-        typename boost::enable_if<boost::core::detail::is_same<End, Ch const*> >::type* = 0 ) BOOST_NOEXCEPT: p_( first ), n_( last - first )
+        typename boost::enable_if<boost::core::detail::is_same<End, Ch const*> >::type* = 0 ) BOOST_NOEXCEPT: p_( first ), n_( static_cast<size_type>( last - first ) )
     {
         BOOST_ASSERT( last - first >= 0 );
     }
@@ -681,7 +681,7 @@ template<class Ch> class basic_string_view
 
         Ch const* r = traits_type::find( data() + pos, size() - pos, c );
 
-        return r? r - data(): npos;
+        return r? static_cast<size_type>( r - data() ): npos;
     }
 
     BOOST_CXX14_CONSTEXPR size_type find( Ch const* s, size_type pos, size_type n ) const BOOST_NOEXCEPT
@@ -696,11 +696,11 @@ template<class Ch> class basic_string_view
 
         for( ;; )
         {
-            p = traits_type::find( p, last - p, s[0] );
+            p = traits_type::find( p, static_cast<size_type>( last - p ), s[0] );
 
             if( p == 0 ) break;
 
-            if( traits_type::compare( p + 1, s + 1, n - 1 ) == 0 ) return p - data();
+            if( traits_type::compare( p + 1, s + 1, n - 1 ) == 0 ) return static_cast<size_type>( p - data() );
 
             ++p;
         }
@@ -1193,7 +1193,7 @@ template<class Ch> class basic_string_view
 template<class Ch> std::basic_ostream<Ch>& operator<<( std::basic_ostream<Ch>& os, basic_string_view<Ch> str )
 {
     Ch const* p = str.data();
-    std::streamsize n = str.size();
+    std::streamsize n = static_cast<std::streamsize>( str.size() );
 
     std::streamsize m = os.width();
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/core/empty_value.hpp b/src/cxx_supportlib/vendor-modified/boost/core/empty_value.hpp
index d8ffa30b4b..5eeee51f9d 100644
--- a/src/cxx_supportlib/vendor-modified/boost/core/empty_value.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/core/empty_value.hpp
@@ -95,9 +95,57 @@ class empty_value {
 };
 
 #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
+#if defined(BOOST_MSVC)
+/*
+This is a workaround to an MSVC bug when T is a nested class:
+https://developercommunity.visualstudio.com/t/Compiler-bug:-Incorrect-C2247-and-C2248/10690025
+*/
+namespace detail {
+
+template<class T>
+class empty_value_base
+    : public T {
+public:
+#if !defined(BOOST_NO_CXX11_DEFAULTED_FUNCTIONS)
+    empty_value_base() = default;
+#else
+    BOOST_CONSTEXPR empty_value_base() { }
+#endif
+
+#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
+#if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
+    template<class U, class... Args>
+    BOOST_CONSTEXPR empty_value_base(U&& value, Args&&... args)
+        : T(std::forward<U>(value), std::forward<Args>(args)...) { }
+#else
+    template<class U>
+    BOOST_CONSTEXPR empty_value_base(U&& value)
+        : T(std::forward<U>(value)) { }
+#endif
+#else
+    template<class U>
+    BOOST_CONSTEXPR empty_value_base(const U& value)
+        : T(value) { }
+
+    template<class U>
+    BOOST_CONSTEXPR empty_value_base(U& value)
+        : T(value) { }
+#endif
+};
+
+} /* detail */
+#endif
+
 template<class T, unsigned N>
 class empty_value<T, N, true>
+#if defined(BOOST_MSVC)
+    : detail::empty_value_base<T> {
+    typedef detail::empty_value_base<T> empty_base_;
+#else
     : T {
+    typedef T empty_base_;
+#endif
+
 public:
     typedef T type;
 
@@ -108,26 +156,26 @@ class empty_value<T, N, true>
 #endif
 
     BOOST_CONSTEXPR empty_value(boost::empty_init_t)
-        : T() { }
+        : empty_base_() { }
 
 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
 #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
     template<class U, class... Args>
     BOOST_CONSTEXPR empty_value(boost::empty_init_t, U&& value, Args&&... args)
-        : T(std::forward<U>(value), std::forward<Args>(args)...) { }
+        : empty_base_(std::forward<U>(value), std::forward<Args>(args)...) { }
 #else
     template<class U>
     BOOST_CONSTEXPR empty_value(boost::empty_init_t, U&& value)
-        : T(std::forward<U>(value)) { }
+        : empty_base_(std::forward<U>(value)) { }
 #endif
 #else
     template<class U>
     BOOST_CONSTEXPR empty_value(boost::empty_init_t, const U& value)
-        : T(value) { }
+        : empty_base_(value) { }
 
     template<class U>
     BOOST_CONSTEXPR empty_value(boost::empty_init_t, U& value)
-        : T(value) { }
+        : empty_base_(value) { }
 #endif
 
     BOOST_CONSTEXPR const T& get() const BOOST_NOEXCEPT {
diff --git a/src/cxx_supportlib/vendor-modified/boost/core/lightweight_test.hpp b/src/cxx_supportlib/vendor-modified/boost/core/lightweight_test.hpp
index c09ce8734a..43baea0559 100644
--- a/src/cxx_supportlib/vendor-modified/boost/core/lightweight_test.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/core/lightweight_test.hpp
@@ -153,6 +153,7 @@ inline void no_throw_failed_impl(const char* expr, const char* what, const char*
 #elif defined(__GNUC__) && !(defined(__INTEL_COMPILER) || defined(__ICL) || defined(__ICC) || defined(__ECC)) && (__GNUC__ * 100 + __GNUC_MINOR__) >= 406
 # pragma GCC diagnostic push
 # pragma GCC diagnostic ignored "-Wsign-compare"
+# pragma GCC diagnostic ignored "-Wsign-conversion"
 #endif
 
 // specialize test output for char pointers to avoid printing as cstring
diff --git a/src/cxx_supportlib/vendor-modified/boost/core/pointer_in_range.hpp b/src/cxx_supportlib/vendor-modified/boost/core/pointer_in_range.hpp
new file mode 100644
index 0000000000..4957ff8581
--- /dev/null
+++ b/src/cxx_supportlib/vendor-modified/boost/core/pointer_in_range.hpp
@@ -0,0 +1,49 @@
+/*
+Copyright 2024 Glen Joseph Fernandes
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+*/
+#ifndef BOOST_CORE_POINTER_IN_RANGE_HPP
+#define BOOST_CORE_POINTER_IN_RANGE_HPP
+
+#include <boost/config.hpp>
+#include <functional>
+
+#if !defined(BOOST_NO_CXX14_CONSTEXPR)
+#if defined(BOOST_MSVC) && BOOST_MSVC >= 1925
+#define BOOST_CORE_DETAIL_HAS_IS_CONSTEVAL
+#elif defined(__has_builtin)
+#if __has_builtin(__builtin_is_constant_evaluated)
+#define BOOST_CORE_DETAIL_HAS_IS_CONSTEVAL
+#endif
+#endif
+#endif
+
+#if !defined(BOOST_CORE_DETAIL_HAS_IS_CONSTEVAL)
+#define BOOST_CORE_NO_CONSTEXPR_POINTER_IN_RANGE
+#endif
+
+namespace boost {
+
+template<class T>
+inline BOOST_CONSTEXPR bool
+pointer_in_range(const T* p, const T* b, const T* e)
+{
+#if defined(BOOST_CORE_DETAIL_HAS_IS_CONSTEVAL)
+    if ( __builtin_is_constant_evaluated()) {
+        for (; b != e; ++b) {
+            if (b == p) {
+                return true;
+            }
+        }
+        return false;
+    }
+#endif
+    return std::less_equal<const T*>()(b, p) && std::less<const T*>()(p, e);
+}
+
+} /* boost */
+
+#endif
diff --git a/src/cxx_supportlib/vendor-modified/boost/core/span.hpp b/src/cxx_supportlib/vendor-modified/boost/core/span.hpp
index 99a2dd7f03..2e64262dca 100644
--- a/src/cxx_supportlib/vendor-modified/boost/core/span.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/core/span.hpp
@@ -351,8 +351,10 @@ class span {
     detail::span_store<T, E> s_;
 };
 
+#if defined(BOOST_NO_CXX17_INLINE_VARIABLES)
 template<class T, std::size_t E>
 constexpr std::size_t span<T, E>::extent;
+#endif
 
 #ifdef __cpp_deduction_guides
 template<class I, class L>
diff --git a/src/cxx_supportlib/vendor-modified/boost/core/type_name.hpp b/src/cxx_supportlib/vendor-modified/boost/core/type_name.hpp
index 773b5f681d..81e00c2031 100644
--- a/src/cxx_supportlib/vendor-modified/boost/core/type_name.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/core/type_name.hpp
@@ -103,7 +103,8 @@ inline std::string fix_typeid_name( char const* n )
 }
 
 // class types can be incomplete
-template<class T> std::string typeid_name_impl( int T::* )
+// but also abstract (T[1] doesn't form)
+template<class T> std::string typeid_name_impl( int T::*, T(*)[1] )
 {
     std::string r = fix_typeid_name( typeid(T[1]).name() );
     return r.substr( 0, r.size() - 4 ); // remove ' [1]' suffix
@@ -116,7 +117,7 @@ template<class T> std::string typeid_name_impl( ... )
 
 template<class T> std::string typeid_name()
 {
-    return typeid_name_impl<T>( 0 );
+    return typeid_name_impl<T>( 0, 0 );
 }
 
 // template names
@@ -345,6 +346,8 @@ template<> struct tn_holder<boost::uint128_type>
 
 #endif
 
+#if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
+
 template<> struct tn_holder<wchar_t>
 {
     static std::string type_name( std::string const& suffix )
@@ -353,6 +356,8 @@ template<> struct tn_holder<wchar_t>
     }
 };
 
+#endif
+
 #if !defined(BOOST_NO_CXX11_CHAR16_T)
 
 template<> struct tn_holder<char16_t>
diff --git a/src/cxx_supportlib/vendor-modified/boost/function/function_base.hpp b/src/cxx_supportlib/vendor-modified/boost/function/function_base.hpp
index 7f78e36eca..ca15b7b7bb 100644
--- a/src/cxx_supportlib/vendor-modified/boost/function/function_base.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/function/function_base.hpp
@@ -15,17 +15,6 @@
 #include <boost/function_equal.hpp>
 #include <boost/core/typeinfo.hpp>
 #include <boost/core/ref.hpp>
-#include <boost/type_traits/has_trivial_copy.hpp>
-#include <boost/type_traits/has_trivial_destructor.hpp>
-#include <boost/type_traits/is_const.hpp>
-#include <boost/type_traits/is_integral.hpp>
-#include <boost/type_traits/is_volatile.hpp>
-#include <boost/type_traits/composite_traits.hpp>
-#include <boost/type_traits/conditional.hpp>
-#include <boost/type_traits/alignment_of.hpp>
-#include <boost/type_traits/enable_if.hpp>
-#include <boost/type_traits/integral_constant.hpp>
-#include <boost/type_traits/is_function.hpp>
 #include <boost/assert.hpp>
 #include <boost/config.hpp>
 #include <boost/config/workaround.hpp>
@@ -33,6 +22,7 @@
 #include <string>
 #include <memory>
 #include <new>
+#include <type_traits>
 
 #if defined(BOOST_MSVC)
 #   pragma warning( push )
@@ -43,10 +33,8 @@
 // retained because used in a test
 #define BOOST_FUNCTION_TARGET_FIX(x)
 
-#  define BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor,Type)              \
-      typename ::boost::enable_if_<          \
-                           !(::boost::is_integral<Functor>::value), \
-                           Type>::type
+#define BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor,Type) \
+  typename std::enable_if< !std::is_integral<Functor>::value, Type>::type
 
 namespace boost {
   namespace detail {
@@ -131,15 +119,15 @@ namespace boost {
       template<typename F>
       class get_function_tag
       {
-        typedef typename conditional<(is_pointer<F>::value),
+        typedef typename std::conditional<std::is_pointer<F>::value,
                                    function_ptr_tag,
                                    function_obj_tag>::type ptr_or_obj_tag;
 
-        typedef typename conditional<(is_member_pointer<F>::value),
+        typedef typename std::conditional<std::is_member_pointer<F>::value,
                                    member_ptr_tag,
                                    ptr_or_obj_tag>::type ptr_or_obj_or_mem_tag;
 
-        typedef typename conditional<(is_reference_wrapper<F>::value),
+        typedef typename std::conditional<is_reference_wrapper<F>::value,
                                    function_obj_ref_tag,
                                    ptr_or_obj_or_mem_tag>::type or_ref_tag;
 
@@ -204,8 +192,8 @@ namespace boost {
         BOOST_STATIC_CONSTANT
           (bool,
            value = ((sizeof(F) <= sizeof(function_buffer) &&
-                     (alignment_of<function_buffer>::value
-                      % alignment_of<F>::value == 0))));
+                     (std::alignment_of<function_buffer>::value
+                      % std::alignment_of<F>::value == 0))));
       };
 
       template <typename F,typename A>
@@ -306,7 +294,7 @@ namespace boost {
         // Function objects that fit in the small-object buffer.
         static inline void
         manager(const function_buffer& in_buffer, function_buffer& out_buffer,
-                functor_manager_operation_type op, true_type)
+                functor_manager_operation_type op, std::true_type)
         {
           functor_manager_common<Functor>::manage_small(in_buffer,out_buffer,op);
         }
@@ -314,7 +302,7 @@ namespace boost {
         // Function objects that require heap allocation
         static inline void
         manager(const function_buffer& in_buffer, function_buffer& out_buffer,
-                functor_manager_operation_type op, false_type)
+                functor_manager_operation_type op, std::false_type)
         {
           if (op == clone_functor_tag) {
             // Clone the functor
@@ -355,7 +343,7 @@ namespace boost {
                 functor_manager_operation_type op, function_obj_tag)
         {
           manager(in_buffer, out_buffer, op,
-                  integral_constant<bool, (function_allows_small_object_optimization<functor_type>::value)>());
+                  std::integral_constant<bool, (function_allows_small_object_optimization<functor_type>::value)>());
         }
 
         // For member pointers, we use the small-object optimization buffer.
@@ -363,7 +351,7 @@ namespace boost {
         manager(const function_buffer& in_buffer, function_buffer& out_buffer,
                 functor_manager_operation_type op, member_ptr_tag)
         {
-          manager(in_buffer, out_buffer, op, true_type());
+          manager(in_buffer, out_buffer, op, std::true_type());
         }
 
       public:
@@ -401,7 +389,7 @@ namespace boost {
         // Function objects that fit in the small-object buffer.
         static inline void
         manager(const function_buffer& in_buffer, function_buffer& out_buffer,
-                functor_manager_operation_type op, true_type)
+                functor_manager_operation_type op, std::true_type)
         {
           functor_manager_common<Functor>::manage_small(in_buffer,out_buffer,op);
         }
@@ -409,7 +397,7 @@ namespace boost {
         // Function objects that require heap allocation
         static inline void
         manager(const function_buffer& in_buffer, function_buffer& out_buffer,
-                functor_manager_operation_type op, false_type)
+                functor_manager_operation_type op, std::false_type)
         {
           typedef functor_wrapper<Functor,Allocator> functor_wrapper_type;
 
@@ -460,7 +448,7 @@ namespace boost {
                 functor_manager_operation_type op, function_obj_tag)
         {
           manager(in_buffer, out_buffer, op,
-                  integral_constant<bool, (function_allows_small_object_optimization<functor_type>::value)>());
+                  std::integral_constant<bool, (function_allows_small_object_optimization<functor_type>::value)>());
         }
 
       public:
@@ -529,8 +517,8 @@ class function_base
 
       detail::function::function_buffer type_result;
       type_result.members.type.type = &BOOST_CORE_TYPEID(Functor);
-      type_result.members.type.const_qualified = is_const<Functor>::value;
-      type_result.members.type.volatile_qualified = is_volatile<Functor>::value;
+      type_result.members.type.const_qualified = std::is_const<Functor>::value;
+      type_result.members.type.volatile_qualified = std::is_volatile<Functor>::value;
       get_vtable()->manager(functor, type_result,
                       detail::function::check_functor_type_tag);
       return static_cast<Functor*>(type_result.members.obj_ptr);
@@ -544,7 +532,7 @@ class function_base
       detail::function::function_buffer type_result;
       type_result.members.type.type = &BOOST_CORE_TYPEID(Functor);
       type_result.members.type.const_qualified = true;
-      type_result.members.type.volatile_qualified = is_volatile<Functor>::value;
+      type_result.members.type.volatile_qualified = std::is_volatile<Functor>::value;
       get_vtable()->manager(functor, type_result,
                       detail::function::check_functor_type_tag);
       // GCC 2.95.3 gets the CV qualifiers wrong here, so we
@@ -553,8 +541,8 @@ class function_base
     }
 
   template<typename F>
-    typename boost::enable_if_< !boost::is_function<F>::value, bool >::type
-	contains(const F& f) const
+    typename std::enable_if< !std::is_function<F>::value, bool >::type
+    contains(const F& f) const
     {
       if (const F* fp = this->template target<F>())
       {
@@ -565,8 +553,8 @@ class function_base
     }
 
   template<typename Fn>
-    typename boost::enable_if_< boost::is_function<Fn>::value, bool >::type
-	contains(Fn& f) const
+    typename std::enable_if< std::is_function<Fn>::value, bool >::type
+    contains(Fn& f) const
     {
       typedef Fn* F;
       if (const F* fp = this->template target<F>())
diff --git a/src/cxx_supportlib/vendor-modified/boost/function/function_template.hpp b/src/cxx_supportlib/vendor-modified/boost/function/function_template.hpp
index ee3fc7ab4d..f21a395beb 100644
--- a/src/cxx_supportlib/vendor-modified/boost/function/function_template.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/function/function_template.hpp
@@ -15,11 +15,10 @@
 #include <boost/core/no_exceptions_support.hpp>
 #include <boost/mem_fn.hpp>
 #include <boost/throw_exception.hpp>
-#include <boost/type_traits/is_integral.hpp>
-#include <boost/type_traits/is_void.hpp>
 #include <boost/config.hpp>
 #include <algorithm>
 #include <cassert>
+#include <type_traits>
 
 #if defined(BOOST_MSVC)
 #   pragma warning( push )
@@ -180,7 +179,7 @@ namespace boost {
       >
       struct get_function_invoker
       {
-        typedef typename conditional<(is_void<R>::value),
+        typedef typename std::conditional<std::is_void<R>::value,
                             void_function_invoker<
                             FunctionPtr,
                             R,
@@ -201,7 +200,7 @@ namespace boost {
        >
       struct get_function_obj_invoker
       {
-        typedef typename conditional<(is_void<R>::value),
+        typedef typename std::conditional<std::is_void<R>::value,
                             void_function_obj_invoker<
                             FunctionObj,
                             R,
@@ -222,7 +221,7 @@ namespace boost {
        >
       struct get_function_ref_invoker
       {
-        typedef typename conditional<(is_void<R>::value),
+        typedef typename std::conditional<std::is_void<R>::value,
                             void_function_ref_invoker<
                             FunctionObj,
                             R,
@@ -244,7 +243,7 @@ namespace boost {
        >
       struct get_member_invoker
       {
-        typedef typename conditional<(is_void<R>::value),
+        typedef typename std::conditional<std::is_void<R>::value,
                             void_member_invoker<
                             MemberPtr,
                             R,
@@ -499,27 +498,27 @@ namespace boost {
         // Assign to a function object using the small object optimization
         template<typename FunctionObj>
         void
-        assign_functor(FunctionObj f, function_buffer& functor, true_type) const
+        assign_functor(FunctionObj f, function_buffer& functor, std::true_type) const
         {
           new (reinterpret_cast<void*>(functor.data)) FunctionObj(std::move(f));
         }
         template<typename FunctionObj,typename Allocator>
         void
-        assign_functor_a(FunctionObj f, function_buffer& functor, Allocator, true_type) const
+        assign_functor_a(FunctionObj f, function_buffer& functor, Allocator, std::true_type) const
         {
-          assign_functor(std::move(f),functor,true_type());
+          assign_functor(std::move(f),functor,std::true_type());
         }
 
         // Assign to a function object allocated on the heap.
         template<typename FunctionObj>
         void
-        assign_functor(FunctionObj f, function_buffer& functor, false_type) const
+        assign_functor(FunctionObj f, function_buffer& functor, std::false_type) const
         {
           functor.members.obj_ptr = new FunctionObj(std::move(f));
         }
         template<typename FunctionObj,typename Allocator>
         void
-        assign_functor_a(FunctionObj f, function_buffer& functor, Allocator a, false_type) const
+        assign_functor_a(FunctionObj f, function_buffer& functor, Allocator a, std::false_type) const
         {
           typedef functor_wrapper<FunctionObj,Allocator> functor_wrapper_type;
 
@@ -540,7 +539,7 @@ namespace boost {
         {
           if (!boost::detail::function::has_empty_target(boost::addressof(f))) {
             assign_functor(std::move(f), functor,
-                           integral_constant<bool, (function_allows_small_object_optimization<FunctionObj>::value)>());
+                           std::integral_constant<bool, (function_allows_small_object_optimization<FunctionObj>::value)>());
             return true;
           } else {
             return false;
@@ -552,7 +551,7 @@ namespace boost {
         {
           if (!boost::detail::function::has_empty_target(boost::addressof(f))) {
             assign_functor_a(std::move(f), functor, a,
-                           integral_constant<bool, (function_allows_small_object_optimization<FunctionObj>::value)>());
+                           std::integral_constant<bool, (function_allows_small_object_optimization<FunctionObj>::value)>());
             return true;
           } else {
             return false;
@@ -566,8 +565,8 @@ namespace boost {
                   function_buffer& functor, function_obj_ref_tag) const
         {
           functor.members.obj_ref.obj_ptr = (void *)(f.get_pointer());
-          functor.members.obj_ref.is_const_qualified = is_const<FunctionObj>::value;
-          functor.members.obj_ref.is_volatile_qualified = is_volatile<FunctionObj>::value;
+          functor.members.obj_ref.is_const_qualified = std::is_const<FunctionObj>::value;
+          functor.members.obj_ref.is_volatile_qualified = std::is_volatile<FunctionObj>::value;
           return true;
         }
         template<typename FunctionObj,typename Allocator>
@@ -587,19 +586,125 @@ namespace boost {
       struct variadic_function_base
       {};
 
-      template <typename T>
-      struct variadic_function_base<T>
+      template <typename T1>
+      struct variadic_function_base<T1>
       {
-        typedef T argument_type;
+        typedef T1 argument_type;
+        typedef T1 arg1_type;
       };
 
-      template <typename T0, typename T1>
-      struct variadic_function_base<T0, T1>
+      template <typename T1, typename T2>
+      struct variadic_function_base<T1, T2>
       {
-        typedef T0 first_argument_type;
-        typedef T1 second_argument_type;
+        typedef T1 first_argument_type;
+        typedef T2 second_argument_type;
+        typedef T1 arg1_type;
+        typedef T2 arg2_type;
       };
 
+      template <typename T1, typename T2, typename T3>
+      struct variadic_function_base<T1, T2, T3>
+      {
+        typedef T1 arg1_type;
+        typedef T2 arg2_type;
+        typedef T3 arg3_type;
+      };
+
+      template <typename T1, typename T2, typename T3, typename T4>
+      struct variadic_function_base<T1, T2, T3, T4>
+      {
+        typedef T1 arg1_type;
+        typedef T2 arg2_type;
+        typedef T3 arg3_type;
+        typedef T4 arg4_type;
+      };
+
+      template <typename T1, typename T2, typename T3, typename T4, typename T5>
+      struct variadic_function_base<T1, T2, T3, T4, T5>
+      {
+        typedef T1 arg1_type;
+        typedef T2 arg2_type;
+        typedef T3 arg3_type;
+        typedef T4 arg4_type;
+        typedef T5 arg5_type;
+      };
+
+      template <typename T1, typename T2, typename T3, typename T4, typename T5, typename T6>
+      struct variadic_function_base<T1, T2, T3, T4, T5, T6>
+      {
+        typedef T1 arg1_type;
+        typedef T2 arg2_type;
+        typedef T3 arg3_type;
+        typedef T4 arg4_type;
+        typedef T5 arg5_type;
+        typedef T6 arg6_type;
+      };
+
+      template <typename T1, typename T2, typename T3, typename T4, typename T5, typename T6, typename T7>
+      struct variadic_function_base<T1, T2, T3, T4, T5, T6, T7>
+      {
+        typedef T1 arg1_type;
+        typedef T2 arg2_type;
+        typedef T3 arg3_type;
+        typedef T4 arg4_type;
+        typedef T5 arg5_type;
+        typedef T6 arg6_type;
+        typedef T7 arg7_type;
+      };
+
+      template <typename T1, typename T2, typename T3, typename T4, typename T5, typename T6, typename T7, typename T8>
+      struct variadic_function_base<T1, T2, T3, T4, T5, T6, T7, T8>
+      {
+        typedef T1 arg1_type;
+        typedef T2 arg2_type;
+        typedef T3 arg3_type;
+        typedef T4 arg4_type;
+        typedef T5 arg5_type;
+        typedef T6 arg6_type;
+        typedef T7 arg7_type;
+        typedef T8 arg8_type;
+      };
+
+      template <typename T1, typename T2, typename T3, typename T4, typename T5, typename T6, typename T7, typename T8, typename T9>
+      struct variadic_function_base<T1, T2, T3, T4, T5, T6, T7, T8, T9>
+      {
+        typedef T1 arg1_type;
+        typedef T2 arg2_type;
+        typedef T3 arg3_type;
+        typedef T4 arg4_type;
+        typedef T5 arg5_type;
+        typedef T6 arg6_type;
+        typedef T7 arg7_type;
+        typedef T8 arg8_type;
+        typedef T9 arg9_type;
+      };
+
+      template <typename T1, typename T2, typename T3, typename T4, typename T5, typename T6, typename T7, typename T8, typename T9, typename T10>
+      struct variadic_function_base<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>
+      {
+        typedef T1 arg1_type;
+        typedef T2 arg2_type;
+        typedef T3 arg3_type;
+        typedef T4 arg4_type;
+        typedef T5 arg5_type;
+        typedef T6 arg6_type;
+        typedef T7 arg7_type;
+        typedef T8 arg8_type;
+        typedef T9 arg9_type;
+        typedef T10 arg10_type;
+      };
+
+#if defined( BOOST_LIBSTDCXX_VERSION ) && BOOST_LIBSTDCXX_VERSION < 50000
+
+      template<class T> struct is_trivially_copyable: std::integral_constant<bool,
+        __has_trivial_copy(T) && __has_trivial_assign(T) && __has_trivial_destructor(T)> {};
+
+#else
+
+      using std::is_trivially_copyable;
+
+#endif
+
     } // end namespace function
   } // end namespace detail
 
@@ -643,8 +748,8 @@ namespace boost {
     // one with a default parameter.
     template<typename Functor>
     function_n(Functor f
-                            ,typename boost::enable_if_<
-                             !(is_integral<Functor>::value),
+                            ,typename std::enable_if<
+                             !std::is_integral<Functor>::value,
                                         int>::type = 0
                             ) :
       function_base()
@@ -653,8 +758,8 @@ namespace boost {
     }
     template<typename Functor,typename Allocator>
     function_n(Functor f, Allocator a
-                            ,typename boost::enable_if_<
-                              !(is_integral<Functor>::value),
+                            ,typename std::enable_if<
+                              !std::is_integral<Functor>::value,
                                         int>::type = 0
                             ) :
       function_base()
@@ -691,8 +796,8 @@ namespace boost {
     // handle function_n as the type of the temporary to
     // construct.
     template<typename Functor>
-    typename boost::enable_if_<
-                  !(is_integral<Functor>::value),
+    typename std::enable_if<
+                  !std::is_integral<Functor>::value,
                function_n&>::type
     operator=(Functor f)
     {
@@ -835,8 +940,7 @@ namespace boost {
       if (stored_vtable.assign_to(std::move(f), functor)) {
         std::size_t value = reinterpret_cast<std::size_t>(&stored_vtable.base);
         // coverity[pointless_expression]: suppress coverity warnings on apparant if(const).
-        if (boost::has_trivial_copy_constructor<Functor>::value &&
-            boost::has_trivial_destructor<Functor>::value &&
+        if (boost::detail::function::is_trivially_copyable<Functor>::value &&
             boost::detail::function::function_allows_small_object_optimization<Functor>::value)
           value |= static_cast<std::size_t>(0x01);
         vtable = reinterpret_cast<boost::detail::function::vtable_base *>(value);
@@ -869,8 +973,7 @@ namespace boost {
       if (stored_vtable.assign_to_a(std::move(f), functor, a)) {
         std::size_t value = reinterpret_cast<std::size_t>(&stored_vtable.base);
         // coverity[pointless_expression]: suppress coverity warnings on apparant if(const).
-        if (boost::has_trivial_copy_constructor<Functor>::value &&
-            boost::has_trivial_destructor<Functor>::value &&
+        if (boost::detail::function::is_trivially_copyable<Functor>::value &&
             boost::detail::function::function_allows_small_object_optimization<Functor>::value)
           value |= static_cast<std::size_t>(0x01);
         vtable = reinterpret_cast<boost::detail::function::vtable_base *>(value);
@@ -974,8 +1077,8 @@ class function<R (T...)>
 
   template<typename Functor>
   function(Functor f
-           ,typename boost::enable_if_<
-                          !(is_integral<Functor>::value),
+           ,typename std::enable_if<
+                          !std::is_integral<Functor>::value,
                        int>::type = 0
            ) :
     base_type(std::move(f))
@@ -983,8 +1086,8 @@ class function<R (T...)>
   }
   template<typename Functor,typename Allocator>
   function(Functor f, Allocator a
-           ,typename boost::enable_if_<
-                           !(is_integral<Functor>::value),
+           ,typename std::enable_if<
+                           !std::is_integral<Functor>::value,
                        int>::type = 0
            ) :
     base_type(std::move(f),a)
@@ -1014,8 +1117,8 @@ class function<R (T...)>
   }
 
   template<typename Functor>
-  typename boost::enable_if_<
-                         !(is_integral<Functor>::value),
+  typename std::enable_if<
+                         !std::is_integral<Functor>::value,
                       self_type&>::type
   operator=(Functor f)
   {
diff --git a/src/cxx_supportlib/vendor-modified/boost/intrusive/detail/algorithm.hpp b/src/cxx_supportlib/vendor-modified/boost/intrusive/detail/algorithm.hpp
index d2421ffaad..f20c9d1030 100644
--- a/src/cxx_supportlib/vendor-modified/boost/intrusive/detail/algorithm.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/intrusive/detail/algorithm.hpp
@@ -26,15 +26,15 @@ namespace intrusive {
 
 struct algo_pred_equal
 {
-   template<class T>
-   bool operator()(const T &x, const T &y) const
+   template<class T, class T2>
+   bool operator()(const T &x, const T2 &y) const
    {  return x == y;  }
 };
 
 struct algo_pred_less
 {
-   template<class T>
-   bool operator()(const T &x, const T &y) const
+   template<class T, class T2>
+   bool operator()(const T &x, const T2 &y) const
    {  return x < y;  }
 };
 
@@ -49,10 +49,6 @@ bool algo_equal(InputIt1 first1, InputIt1 last1, InputIt2 first2, BinaryPredicat
     return true;
 }
 
-template<class InputIt1, class InputIt2>
-bool algo_equal(InputIt1 first1, InputIt1 last1, InputIt2 first2)
-{  return (algo_equal)(first1, last1, first2, algo_pred_equal());  }
-
 template<class InputIt1, class InputIt2, class BinaryPredicate>
 bool algo_equal(InputIt1 first1, InputIt1 last1, InputIt2 first2, InputIt2 last2, BinaryPredicate pred)
 {
@@ -62,6 +58,10 @@ bool algo_equal(InputIt1 first1, InputIt1 last1, InputIt2 first2, InputIt2 last2
     return first1 == last1 && first2 == last2;
 }
 
+template<class InputIt1, class InputIt2>
+bool algo_equal(InputIt1 first1, InputIt1 last1, InputIt2 first2)
+{  return (algo_equal)(first1, last1, first2, algo_pred_equal());  }
+
 template<class InputIt1, class InputIt2>
 bool algo_equal(InputIt1 first1, InputIt1 last1, InputIt2 first2, InputIt2 last2)
 {  return (algo_equal)(first1, last1, first2, last2, algo_pred_equal());  }
diff --git a/src/cxx_supportlib/vendor-modified/boost/intrusive/detail/hash.hpp b/src/cxx_supportlib/vendor-modified/boost/intrusive/detail/hash.hpp
index 3ddfa2ce23..a18aa3abbe 100644
--- a/src/cxx_supportlib/vendor-modified/boost/intrusive/detail/hash.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/intrusive/detail/hash.hpp
@@ -2,7 +2,7 @@
 //
 // Copyright 2005-2014 Daniel James.
 // Copyright 2021, 2022 Peter Dimov.
-// Copyright 2024 Ion Gaztañaga.
+// Copyright 2024 Ion Gaztanaga.
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 //
diff --git a/src/cxx_supportlib/vendor-modified/boost/intrusive/detail/hook_traits.hpp b/src/cxx_supportlib/vendor-modified/boost/intrusive/detail/hook_traits.hpp
index c33ede0dcd..bc51cdebeb 100644
--- a/src/cxx_supportlib/vendor-modified/boost/intrusive/detail/hook_traits.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/intrusive/detail/hook_traits.hpp
@@ -46,6 +46,10 @@ struct bhtraits_base
       template rebind_pointer<T>::type                               pointer;
    typedef typename pointer_traits<node_ptr>::
       template rebind_pointer<const T>::type                         const_pointer;
+   typedef typename pointer_traits<node_ptr>::
+      template rebind_pointer<node_holder_type>::type                node_holder_ptr;
+   typedef typename pointer_traits<node_ptr>::
+      template rebind_pointer<const node_holder_type>::type          const_node_holder_ptr;
    typedef T &                                                       reference;
    typedef const T &                                                 const_reference;
    typedef node_holder_type &                                        node_holder_reference;
@@ -55,16 +59,14 @@ struct bhtraits_base
 
    inline static pointer to_value_ptr(node_ptr n)
    {
-      pointer p = pointer_traits<pointer>::pointer_to
-         (static_cast<reference>(static_cast<node_holder_reference>(*n)));
-      return p;
+      return pointer_traits<pointer>::
+         static_cast_from(pointer_traits<node_holder_ptr>::static_cast_from(n));
    }
 
    inline static const_pointer to_value_ptr(const_node_ptr n)
    {
-      const_pointer p = pointer_traits<const_pointer>::pointer_to
-         (static_cast<const_reference>(static_cast<const_node_holder_reference>(*n)));
-      return p;
+      return pointer_traits<const_pointer>::
+         static_cast_from(pointer_traits<const_node_holder_ptr>::static_cast_from(n));
    }
 
    inline static node_ptr to_node_ptr(reference value)
diff --git a/src/cxx_supportlib/vendor-modified/boost/intrusive/pointer_traits.hpp b/src/cxx_supportlib/vendor-modified/boost/intrusive/pointer_traits.hpp
index 48d984eef6..1b2ed05763 100644
--- a/src/cxx_supportlib/vendor-modified/boost/intrusive/pointer_traits.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/intrusive/pointer_traits.hpp
@@ -130,7 +130,7 @@ struct pointer_traits
    //!
    //! <b>Note</b>: For non-conforming compilers only the existence of a member function called
    //!   <code>pointer_to</code> is checked.
-   inline static pointer pointer_to(reference r) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer pointer_to(reference r) BOOST_NOEXCEPT
    {
       //Non-standard extension, it does not require Ptr::pointer_to. If not present
       //tries to converts &r to pointer.
@@ -150,7 +150,7 @@ struct pointer_traits
    //! <b>Note</b>: For non-conforming compilers only the existence of a member function called
    //!   <code>static_cast_from</code> is checked.
    template<class UPtr>
-   inline static pointer static_cast_from(const UPtr &uptr) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer static_cast_from(const UPtr &uptr) BOOST_NOEXCEPT
    {
       typedef const UPtr &RefArg;
       const bool value = boost::intrusive::detail::
@@ -171,7 +171,7 @@ struct pointer_traits
    //! <b>Note</b>: For non-conforming compilers only the existence of a member function called
    //!   <code>const_cast_from</code> is checked.
    template<class UPtr>
-   inline static pointer const_cast_from(const UPtr &uptr) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer const_cast_from(const UPtr &uptr) BOOST_NOEXCEPT
    {
       typedef const UPtr &RefArg;
       const bool value = boost::intrusive::detail::
@@ -192,7 +192,7 @@ struct pointer_traits
    //! <b>Note</b>: For non-conforming compilers only the existence of a member function called
    //!   <code>dynamic_cast_from</code> is checked.
    template<class UPtr>
-   inline static pointer dynamic_cast_from(const UPtr &uptr) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer dynamic_cast_from(const UPtr &uptr) BOOST_NOEXCEPT
    {
       typedef const UPtr &RefArg;
       const bool value = boost::intrusive::detail::
@@ -208,46 +208,46 @@ struct pointer_traits
    private:
    //priv_to_raw_pointer
    template <class T>
-   inline static T* to_raw_pointer(T* p) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static T* to_raw_pointer(T* p) BOOST_NOEXCEPT
    {  return p; }
 
    template <class Pointer>
-   inline static typename pointer_traits<Pointer>::element_type*
+   BOOST_INTRUSIVE_FORCEINLINE static typename pointer_traits<Pointer>::element_type*
       to_raw_pointer(const Pointer &p) BOOST_NOEXCEPT
    {  return pointer_traits::to_raw_pointer(p.operator->());  }
 
    //priv_pointer_to
-   inline static pointer priv_pointer_to(boost::intrusive::detail::true_, reference r) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer priv_pointer_to(boost::intrusive::detail::true_, reference r) BOOST_NOEXCEPT
    { return Ptr::pointer_to(r); }
 
-   inline static pointer priv_pointer_to(boost::intrusive::detail::false_, reference r) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer priv_pointer_to(boost::intrusive::detail::false_, reference r) BOOST_NOEXCEPT
    { return pointer(boost::intrusive::detail::addressof(r)); }
 
    //priv_static_cast_from
    template<class UPtr>
-   inline static pointer priv_static_cast_from(boost::intrusive::detail::true_, const UPtr &uptr) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer priv_static_cast_from(boost::intrusive::detail::true_, const UPtr &uptr) BOOST_NOEXCEPT
    { return Ptr::static_cast_from(uptr); }
 
    template<class UPtr>
-   inline static pointer priv_static_cast_from(boost::intrusive::detail::false_, const UPtr &uptr) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer priv_static_cast_from(boost::intrusive::detail::false_, const UPtr &uptr) BOOST_NOEXCEPT
    {  return uptr ? pointer_to(*static_cast<element_type*>(to_raw_pointer(uptr))) : pointer();  }
 
    //priv_const_cast_from
    template<class UPtr>
-   inline static pointer priv_const_cast_from(boost::intrusive::detail::true_, const UPtr &uptr) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer priv_const_cast_from(boost::intrusive::detail::true_, const UPtr &uptr) BOOST_NOEXCEPT
    { return Ptr::const_cast_from(uptr); }
 
    template<class UPtr>
-   inline static pointer priv_const_cast_from(boost::intrusive::detail::false_, const UPtr &uptr) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer priv_const_cast_from(boost::intrusive::detail::false_, const UPtr &uptr) BOOST_NOEXCEPT
    {  return uptr ? pointer_to(const_cast<element_type&>(*uptr)) : pointer();  }
 
    //priv_dynamic_cast_from
    template<class UPtr>
-   inline static pointer priv_dynamic_cast_from(boost::intrusive::detail::true_, const UPtr &uptr) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer priv_dynamic_cast_from(boost::intrusive::detail::true_, const UPtr &uptr) BOOST_NOEXCEPT
    { return Ptr::dynamic_cast_from(uptr); }
 
    template<class UPtr>
-   inline static pointer priv_dynamic_cast_from(boost::intrusive::detail::false_, const UPtr &uptr) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer priv_dynamic_cast_from(boost::intrusive::detail::false_, const UPtr &uptr) BOOST_NOEXCEPT
    {  return uptr ? pointer_to(dynamic_cast<element_type&>(*uptr)) : pointer();  }
    ///@endcond
 };
@@ -296,25 +296,25 @@ struct pointer_traits<T*>
 
    //! <b>Returns</b>: addressof(r)
    //!
-   inline static pointer pointer_to(reference r) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer pointer_to(reference r) BOOST_NOEXCEPT
    { return boost::intrusive::detail::addressof(r); }
 
    //! <b>Returns</b>: static_cast<pointer>(uptr)
    //!
    template<class U>
-   inline static pointer static_cast_from(U *uptr) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer static_cast_from(U *uptr) BOOST_NOEXCEPT
    {  return static_cast<pointer>(uptr);  }
 
    //! <b>Returns</b>: const_cast<pointer>(uptr)
    //!
    template<class U>
-   inline static pointer const_cast_from(U *uptr) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer const_cast_from(U *uptr) BOOST_NOEXCEPT
    {  return const_cast<pointer>(uptr);  }
 
    //! <b>Returns</b>: dynamic_cast<pointer>(uptr)
    //!
    template<class U>
-   inline static pointer dynamic_cast_from(U *uptr) BOOST_NOEXCEPT
+   BOOST_INTRUSIVE_FORCEINLINE static pointer dynamic_cast_from(U *uptr) BOOST_NOEXCEPT
    {  return dynamic_cast<pointer>(uptr);  }
 };
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/lexical_cast/detail/converter_lexical_streams.hpp b/src/cxx_supportlib/vendor-modified/boost/lexical_cast/detail/converter_lexical_streams.hpp
index 6398055e4b..192051df27 100644
--- a/src/cxx_supportlib/vendor-modified/boost/lexical_cast/detail/converter_lexical_streams.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/lexical_cast/detail/converter_lexical_streams.hpp
@@ -198,7 +198,6 @@ namespace boost { namespace detail { namespace lcast {
         }
 
         bool shl_real_type(float val, char* begin) {
-            using namespace std;
             const double val_as_double = val;
             finish = start +
                 boost::core::snprintf(begin, CharacterBufferSize,
@@ -207,7 +206,6 @@ namespace boost { namespace detail { namespace lcast {
         }
 
         bool shl_real_type(double val, char* begin) {
-            using namespace std;
             finish = start +
                 boost::core::snprintf(begin, CharacterBufferSize,
                 "%.*g", static_cast<int>(boost::detail::lcast_get_precision<double>()), val);
@@ -216,7 +214,6 @@ namespace boost { namespace detail { namespace lcast {
 
 #ifndef __MINGW32__
         bool shl_real_type(long double val, char* begin) {
-            using namespace std;
             finish = start +
                 boost::core::snprintf(begin, CharacterBufferSize,
                 "%.*Lg", static_cast<int>(boost::detail::lcast_get_precision<long double>()), val );
@@ -228,28 +225,32 @@ namespace boost { namespace detail { namespace lcast {
         }
 #endif
 
-#if !defined(BOOST_LCAST_NO_WCHAR_T) && !defined(BOOST_NO_SWPRINTF) && !defined(__MINGW32__)
+#if !defined(BOOST_LCAST_NO_WCHAR_T)
         bool shl_real_type(float val, wchar_t* begin) {
-            using namespace std;
             const double val_as_double = val;
-            finish = start + swprintf(begin, CharacterBufferSize,
-                                   L"%.*g",
-                                   static_cast<int>(boost::detail::lcast_get_precision<float >()),
-                                   val_as_double );
+            finish = start + boost::core::swprintf(
+                begin, CharacterBufferSize, L"%.*g",
+                static_cast<int>(boost::detail::lcast_get_precision<float >()),
+                val_as_double
+            );
             return finish > start;
         }
 
         bool shl_real_type(double val, wchar_t* begin) {
-            using namespace std;
-            finish = start + swprintf(begin, CharacterBufferSize,
-                                      L"%.*g", static_cast<int>(boost::detail::lcast_get_precision<double >()), val );
+            finish = start + boost::core::swprintf(
+              begin, CharacterBufferSize, L"%.*g",
+              static_cast<int>(boost::detail::lcast_get_precision<double>()),
+              val
+            );
             return finish > start;
         }
 
         bool shl_real_type(long double val, wchar_t* begin) {
-            using namespace std;
-            finish = start + swprintf(begin, CharacterBufferSize,
-                                      L"%.*Lg", static_cast<int>(boost::detail::lcast_get_precision<long double >()), val );
+            finish = start + boost::core::swprintf(
+                begin, CharacterBufferSize, L"%.*Lg",
+                static_cast<int>(boost::detail::lcast_get_precision<long double>()),
+                val
+            );
             return finish > start;
         }
 #endif
@@ -345,13 +346,17 @@ namespace boost { namespace detail { namespace lcast {
         template <class C, class CharTraits>
         enable_if_compatible_char_t<C>
         stream_in(lcast::exact<std::basic_string_view<C, CharTraits>> x) noexcept {
-            return shl_char_array_limited(reinterpret_cast<const CharT*>(x.payload.data()), x.payload.size());
+            start = reinterpret_cast<const CharT*>(x.payload.data());
+            finish = start + x.payload.size();
+            return true;
         }
 #endif
         template <class C, class CharTraits>
         enable_if_compatible_char_t<C>
         stream_in(lcast::exact<boost::basic_string_view<C, CharTraits>> x) noexcept {
-            return shl_char_array_limited(reinterpret_cast<const CharT*>(x.payload.data()), x.payload.size());
+            start = reinterpret_cast<const CharT*>(x.payload.data());
+            finish = start + x.payload.size();
+            return true;
         }
     };
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/libs/random/src/random_device.cpp b/src/cxx_supportlib/vendor-modified/boost/libs/random/src/random_device.cpp
index 35730d0bb6..4719a402cf 100644
--- a/src/cxx_supportlib/vendor-modified/boost/libs/random/src/random_device.cpp
+++ b/src/cxx_supportlib/vendor-modified/boost/libs/random/src/random_device.cpp
@@ -10,7 +10,9 @@
  *
  */
 
-#define BOOST_RANDOM_SOURCE
+#ifndef BOOST_RANDOM_SOURCE
+#  define BOOST_RANDOM_SOURCE
+#endif
 
 #include <boost/random/random_device.hpp>
 #include <boost/config.hpp>
diff --git a/src/cxx_supportlib/vendor-modified/boost/move/detail/config_begin.hpp b/src/cxx_supportlib/vendor-modified/boost/move/detail/config_begin.hpp
index 4e95a4aba7..ded0050183 100644
--- a/src/cxx_supportlib/vendor-modified/boost/move/detail/config_begin.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/move/detail/config_begin.hpp
@@ -16,7 +16,6 @@
 #  pragma warning (disable : 4619) // there is no warning number 'XXXX'
 #  pragma warning (disable : 4324) // structure was padded due to __declspec(align())
 #  pragma warning (disable : 4675) // "function":  resolved overload was found by argument-dependent lookup
-#  pragma warning (disable : 4996) // "function": was declared deprecated (_CRT_SECURE_NO_DEPRECATE/_SCL_SECURE_NO_WARNINGS)
 #  pragma warning (disable : 4714) // "function": marked as __forceinline not inlined
 #  pragma warning (disable : 4127) // conditional expression is constant
 #endif
diff --git a/src/cxx_supportlib/vendor-modified/boost/move/detail/launder.hpp b/src/cxx_supportlib/vendor-modified/boost/move/detail/launder.hpp
new file mode 100644
index 0000000000..a6236de950
--- /dev/null
+++ b/src/cxx_supportlib/vendor-modified/boost/move/detail/launder.hpp
@@ -0,0 +1,53 @@
+//////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Ion Gaztanaga 2014-2015. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying file
+// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See http://www.boost.org/libs/container for documentation.
+//
+//////////////////////////////////////////////////////////////////////////////
+#ifndef BOOST_MOVE_DETAIL_LAUNDER_HPP
+#define BOOST_MOVE_DETAIL_LAUNDER_HPP
+
+#ifndef BOOST_CONFIG_HPP
+#  include <boost/config.hpp>
+#endif
+
+#if defined(BOOST_HAS_PRAGMA_ONCE)
+#  pragma once
+#endif
+
+#include <boost/move/detail/workaround.hpp>
+
+namespace boost {
+namespace move_detail {
+
+#if defined(BOOST_MOVE_HAS_BUILTIN_LAUNDER)
+
+template<class T>
+BOOST_MOVE_FORCEINLINE T* launder(T* p)
+{
+    return __builtin_launder( p );
+}
+
+#else
+
+template<class T>
+BOOST_MOVE_FORCEINLINE T* launder(T* p)
+{
+    return p;
+}
+
+#endif
+
+template<class T>
+BOOST_MOVE_FORCEINLINE T launder_cast(const volatile void* p)
+{
+   return (launder)((T)p);
+}
+
+}  //namespace move_detail {
+}  //namespace boost {
+
+#endif   //#ifndef BOOST_MOVE_DETAIL_LAUNDER_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/move/detail/type_traits.hpp b/src/cxx_supportlib/vendor-modified/boost/move/detail/type_traits.hpp
index 84dcbceb73..de8b2eb6da 100644
--- a/src/cxx_supportlib/vendor-modified/boost/move/detail/type_traits.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/move/detail/type_traits.hpp
@@ -1197,12 +1197,20 @@ struct aligned_struct;
 template <> struct aligned_struct<1> { char data; };
 template <> struct aligned_struct<2> { short data; };
 template <> struct aligned_struct<4> { int data; };
-template <> struct aligned_struct<8> { double data; };
+//8 byte alignment does not propely work in x86 if attribute is not used.
+//If a user declares a variable with 8 byte alignment, such as a double
+//the compiler will not realign the stack.
+// 
+//If _declspec(align) is used MSVC will realign the stack.
+//
+//Disabled specialization
+//template <> struct aligned_struct<8> { double data; };
 
 #define BOOST_MOVE_ALIGNED_STRUCT(x) \
   template <> struct aligned_struct<x> { \
     __declspec(align(x)) char data; \
   }
+BOOST_MOVE_ALIGNED_STRUCT(8);
 BOOST_MOVE_ALIGNED_STRUCT(16);
 BOOST_MOVE_ALIGNED_STRUCT(32);
 BOOST_MOVE_ALIGNED_STRUCT(64);
diff --git a/src/cxx_supportlib/vendor-modified/boost/move/detail/workaround.hpp b/src/cxx_supportlib/vendor-modified/boost/move/detail/workaround.hpp
index 5edfcee1f2..f12e93315e 100644
--- a/src/cxx_supportlib/vendor-modified/boost/move/detail/workaround.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/move/detail/workaround.hpp
@@ -147,5 +147,10 @@ template<unsigned> struct static_assert_test {};
 #define BOOST_MOVE_INTRINSIC_CAST BOOST_MOVE_FORCEINLINE
 #endif
 
-#endif   //#ifndef BOOST_MOVE_DETAIL_WORKAROUND_HPP
+#if defined(__has_builtin)
+#if __has_builtin(__builtin_launder)
+   #define BOOST_MOVE_HAS_BUILTIN_LAUNDER
+#endif
+#endif
 
+#endif   //#ifndef BOOST_MOVE_DETAIL_WORKAROUND_HPP
diff --git a/src/cxx_supportlib/vendor-modified/boost/mp11/version.hpp b/src/cxx_supportlib/vendor-modified/boost/mp11/version.hpp
index aba1fb1ca7..d991a7657f 100644
--- a/src/cxx_supportlib/vendor-modified/boost/mp11/version.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/mp11/version.hpp
@@ -11,6 +11,6 @@
 // Same format as BOOST_VERSION:
 //   major * 100000 + minor * 100 + patch
 
-#define BOOST_MP11_VERSION 108500
+#define BOOST_MP11_VERSION 108600
 
 #endif // #ifndef BOOST_MP11_VERSION_HPP_INCLUDED
diff --git a/src/cxx_supportlib/vendor-modified/boost/mpl/aux_/integral_wrapper.hpp b/src/cxx_supportlib/vendor-modified/boost/mpl/aux_/integral_wrapper.hpp
index 8748fbb93a..5f24b79495 100644
--- a/src/cxx_supportlib/vendor-modified/boost/mpl/aux_/integral_wrapper.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/mpl/aux_/integral_wrapper.hpp
@@ -56,7 +56,8 @@ struct AUX_WRAPPER_NAME
 // have to #ifdef here: some compilers don't like the 'N + 1' form (MSVC),
 // while some other don't like 'value + 1' (Borland), and some don't like
 // either
-#if BOOST_WORKAROUND(__EDG_VERSION__, <= 243)
+#if BOOST_WORKAROUND(__EDG_VERSION__, <= 243) \
+    || __cplusplus >= 201103L
  private:
     BOOST_STATIC_CONSTANT(AUX_WRAPPER_VALUE_TYPE, next_value = BOOST_MPL_AUX_STATIC_CAST(AUX_WRAPPER_VALUE_TYPE, (N + 1)));
     BOOST_STATIC_CONSTANT(AUX_WRAPPER_VALUE_TYPE, prior_value = BOOST_MPL_AUX_STATIC_CAST(AUX_WRAPPER_VALUE_TYPE, (N - 1)));
diff --git a/src/cxx_supportlib/vendor-modified/boost/predef/version.h b/src/cxx_supportlib/vendor-modified/boost/predef/version.h
index 4428eb56e4..ba8f62cecb 100644
--- a/src/cxx_supportlib/vendor-modified/boost/predef/version.h
+++ b/src/cxx_supportlib/vendor-modified/boost/predef/version.h
@@ -10,6 +10,6 @@ Distributed under the Boost Software License, Version 1.0.
 
 #include <boost/predef/version_number.h>
 
-#define BOOST_PREDEF_VERSION BOOST_VERSION_NUMBER(1,15,0)
+#define BOOST_PREDEF_VERSION BOOST_VERSION_NUMBER(1,15,1)
 
 #endif
diff --git a/src/cxx_supportlib/vendor-modified/boost/smart_ptr/detail/requires_cxx11.hpp b/src/cxx_supportlib/vendor-modified/boost/smart_ptr/detail/requires_cxx11.hpp
index f860bef568..f1ed5f6b4e 100644
--- a/src/cxx_supportlib/vendor-modified/boost/smart_ptr/detail/requires_cxx11.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/smart_ptr/detail/requires_cxx11.hpp
@@ -16,7 +16,7 @@
     defined(BOOST_NO_CXX11_NULLPTR) || \
     defined(BOOST_NO_CXX11_SMART_PTR)
 
-BOOST_PRAGMA_MESSAGE("C++03 support was deprecated in Boost.SmartPtr 1.82 and will be removed in Boost.SmartPtr 1.86.")
+BOOST_PRAGMA_MESSAGE("C++03 support was deprecated in Boost.SmartPtr 1.82 and will be removed in Boost.SmartPtr 1.87.")
 
 #endif
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/smart_ptr/detail/sp_has_gcc_intrinsics.hpp b/src/cxx_supportlib/vendor-modified/boost/smart_ptr/detail/sp_has_gcc_intrinsics.hpp
index 2e15f7909e..cf2d897da0 100644
--- a/src/cxx_supportlib/vendor-modified/boost/smart_ptr/detail/sp_has_gcc_intrinsics.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/smart_ptr/detail/sp_has_gcc_intrinsics.hpp
@@ -17,8 +17,11 @@
 // Defines the BOOST_SP_HAS_GCC_INTRINSICS macro if the __atomic_*
 // intrinsics are available.
 
+// Libraries (e.g. Kokkos) sometimes define the __ATOMIC_RELAXED macros,
+// leading to errors under MSVC (https://github.com/boostorg/smart_ptr/pull/112)
 
-#if defined( __ATOMIC_RELAXED ) && defined( __ATOMIC_ACQUIRE ) && defined( __ATOMIC_RELEASE ) && defined( __ATOMIC_ACQ_REL )
+#if defined( __ATOMIC_RELAXED ) && defined( __ATOMIC_ACQUIRE ) && defined( __ATOMIC_RELEASE ) && defined( __ATOMIC_ACQ_REL ) \
+    && !( defined(_MSC_VER) && !defined(__clang__) )
 
 # define BOOST_SP_HAS_GCC_INTRINSICS
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/system/detail/generic_category_message.hpp b/src/cxx_supportlib/vendor-modified/boost/system/detail/generic_category_message.hpp
index ded2db6331..611ce378ea 100644
--- a/src/cxx_supportlib/vendor-modified/boost/system/detail/generic_category_message.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/system/detail/generic_category_message.hpp
@@ -39,7 +39,19 @@ inline char const * strerror_r_helper( int r, char const * buffer ) noexcept
 
 inline char const * generic_error_category_message( int ev, char * buffer, std::size_t len ) noexcept
 {
-    return strerror_r_helper( strerror_r( ev, buffer, len ), buffer );
+    if( buffer != nullptr )
+    {
+        return strerror_r_helper( strerror_r( ev, buffer, len ), buffer );
+    }
+    else
+    {
+        // strerror_r requires non-null buffer pointer
+
+        char tmp[ 1 ] = {};
+        char const* r = strerror_r_helper( strerror_r( ev, tmp, 0 ), buffer );
+
+        return r == tmp? nullptr: r;
+    }
 }
 
 inline std::string generic_error_category_message( int ev )
diff --git a/src/cxx_supportlib/vendor-modified/boost/thread/detail/thread.hpp b/src/cxx_supportlib/vendor-modified/boost/thread/detail/thread.hpp
index ffcb728264..3717311060 100644
--- a/src/cxx_supportlib/vendor-modified/boost/thread/detail/thread.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/thread/detail/thread.hpp
@@ -166,7 +166,7 @@ namespace boost
       typedef thread_attributes attributes;
 
       BOOST_THREAD_MOVABLE_ONLY(thread)
-    protected:
+    private:
 
         struct dummy;
 
@@ -174,7 +174,7 @@ namespace boost
 
         detail::thread_data_ptr thread_info;
 
-    protected:
+    private:
         bool start_thread_noexcept();
         bool start_thread_noexcept(const attributes& attr);
         void start_thread()
diff --git a/src/cxx_supportlib/vendor-modified/boost/thread/exceptions.hpp b/src/cxx_supportlib/vendor-modified/boost/thread/exceptions.hpp
index 5c2d9cb853..2a5094bd5a 100644
--- a/src/cxx_supportlib/vendor-modified/boost/thread/exceptions.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/thread/exceptions.hpp
@@ -21,7 +21,6 @@
 #include <stdexcept>
 #include <boost/system/system_error.hpp>
 #include <boost/system/error_code.hpp>
-#include <oxt/tracable_exception.hpp>
 
 
 #include <boost/config/abi_prefix.hpp>
@@ -31,7 +30,6 @@ namespace boost
 
 #if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
     class BOOST_SYMBOL_VISIBLE thread_interrupted
-      : public oxt::tracable_exception
     {};
 #endif
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/thread/once.hpp b/src/cxx_supportlib/vendor-modified/boost/thread/once.hpp
index d458fb5314..22f95139ae 100644
--- a/src/cxx_supportlib/vendor-modified/boost/thread/once.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/thread/once.hpp
@@ -38,7 +38,7 @@ namespace boost
   // template<class Callable, class ...Args> void
   // call_once(once_flag& flag, Callable&& func, Args&&... args);
 template<typename Function>
-inline void call_once(Function func,boost::once_flag& flag)
+inline void call_once(Function func,once_flag& flag)
 //inline void call_once(void (*func)(),once_flag& flag)
     {
         call_once(flag,func);
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_map.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_map.hpp
index 15f45de23b..b67f2ad3b1 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_map.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_map.hpp
@@ -1,7 +1,7 @@
 /* Fast open-addressing concurrent hashmap.
  *
  * Copyright 2023 Christian Mazakas.
- * Copyright 2023 Joaquin M Lopez Munoz.
+ * Copyright 2023-2024 Joaquin M Lopez Munoz.
  * Distributed under the Boost Software License, Version 1.0.
  * (See accompanying file LICENSE_1_0.txt or copy at
  * http://www.boost.org/LICENSE_1_0.txt)
@@ -75,6 +75,10 @@ namespace boost {
         typename boost::allocator_const_pointer<allocator_type>::type;
       static constexpr size_type bulk_visit_size = table_type::bulk_visit_size;
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+      using stats = typename table_type::stats;
+#endif
+
       concurrent_flat_map()
           : concurrent_flat_map(detail::foa::default_bucket_count)
       {
@@ -714,6 +718,14 @@ namespace boost {
       void rehash(size_type n) { table_.rehash(n); }
       void reserve(size_type n) { table_.reserve(n); }
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+      /// Stats
+      ///
+      stats get_stats() const { return table_.get_stats(); }
+
+      void reset_stats() noexcept { table_.reset_stats(); }
+#endif
+
       /// Observers
       ///
       allocator_type get_allocator() const noexcept
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_map_fwd.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_map_fwd.hpp
index 99fa130cc1..e66f3674c7 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_map_fwd.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_map_fwd.hpp
@@ -1,6 +1,7 @@
 /* Fast open-addressing concurrent hashmap.
  *
  * Copyright 2023 Christian Mazakas.
+ * Copyright 2024 Braden Ganetsky.
  * Distributed under the Boost Software License, Version 1.0.
  * (See accompanying file LICENSE_1_0.txt or copy at
  * http://www.boost.org/LICENSE_1_0.txt)
@@ -11,11 +12,16 @@
 #ifndef BOOST_UNORDERED_CONCURRENT_FLAT_MAP_FWD_HPP
 #define BOOST_UNORDERED_CONCURRENT_FLAT_MAP_FWD_HPP
 
+#include <boost/config.hpp>
 #include <boost/container_hash/hash_fwd.hpp>
 
 #include <functional>
 #include <memory>
 
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+#include <memory_resource>
+#endif
+
 namespace boost {
   namespace unordered {
 
@@ -43,6 +49,15 @@ namespace boost {
     typename concurrent_flat_map<K, T, H, P, A>::size_type erase_if(
       concurrent_flat_map<K, T, H, P, A>& c, Predicate pred);
 
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+    namespace pmr {
+      template <class Key, class T, class Hash = boost::hash<Key>,
+        class Pred = std::equal_to<Key> >
+      using concurrent_flat_map = boost::unordered::concurrent_flat_map<Key, T,
+        Hash, Pred, std::pmr::polymorphic_allocator<std::pair<Key const, T> > >;
+    } // namespace pmr
+#endif
+
   } // namespace unordered
 
   using boost::unordered::concurrent_flat_map;
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_set.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_set.hpp
index 57f20cdd8f..d0665f7162 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_set.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_set.hpp
@@ -1,7 +1,7 @@
 /* Fast open-addressing concurrent hashset.
  *
  * Copyright 2023 Christian Mazakas.
- * Copyright 2023 Joaquin M Lopez Munoz.
+ * Copyright 2023-2024 Joaquin M Lopez Munoz.
  * Distributed under the Boost Software License, Version 1.0.
  * (See accompanying file LICENSE_1_0.txt or copy at
  * http://www.boost.org/LICENSE_1_0.txt)
@@ -72,6 +72,10 @@ namespace boost {
         typename boost::allocator_const_pointer<allocator_type>::type;
       static constexpr size_type bulk_visit_size = table_type::bulk_visit_size;
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+      using stats = typename table_type::stats;
+#endif
+
       concurrent_flat_set()
           : concurrent_flat_set(detail::foa::default_bucket_count)
       {
@@ -582,6 +586,14 @@ namespace boost {
       void rehash(size_type n) { table_.rehash(n); }
       void reserve(size_type n) { table_.reserve(n); }
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+      /// Stats
+      ///
+      stats get_stats() const { return table_.get_stats(); }
+
+      void reset_stats() noexcept { table_.reset_stats(); }
+#endif
+
       /// Observers
       ///
       allocator_type get_allocator() const noexcept
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_set_fwd.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_set_fwd.hpp
index 03bcc5b4e0..1133d9c93c 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_set_fwd.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/concurrent_flat_set_fwd.hpp
@@ -2,6 +2,7 @@
  *
  * Copyright 2023 Christian Mazakas.
  * Copyright 2023 Joaquin M Lopez Munoz.
+ * Copyright 2024 Braden Ganetsky.
  * Distributed under the Boost Software License, Version 1.0.
  * (See accompanying file LICENSE_1_0.txt or copy at
  * http://www.boost.org/LICENSE_1_0.txt)
@@ -12,11 +13,16 @@
 #ifndef BOOST_UNORDERED_CONCURRENT_FLAT_SET_FWD_HPP
 #define BOOST_UNORDERED_CONCURRENT_FLAT_SET_FWD_HPP
 
+#include <boost/config.hpp>
 #include <boost/container_hash/hash_fwd.hpp>
 
 #include <functional>
 #include <memory>
 
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+#include <memory_resource>
+#endif
+
 namespace boost {
   namespace unordered {
 
@@ -44,6 +50,15 @@ namespace boost {
     typename concurrent_flat_set<K, H, P, A>::size_type erase_if(
       concurrent_flat_set<K, H, P, A>& c, Predicate pred);
 
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+    namespace pmr {
+      template <class Key, class Hash = boost::hash<Key>,
+        class Pred = std::equal_to<Key> >
+      using concurrent_flat_set = boost::unordered::concurrent_flat_set<Key,
+        Hash, Pred, std::pmr::polymorphic_allocator<Key> >;
+    } // namespace pmr
+#endif
+
   } // namespace unordered
 
   using boost::unordered::concurrent_flat_set;
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/detail/fca.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/detail/fca.hpp
index 66c8c2502b..1f733db200 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/detail/fca.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/detail/fca.hpp
@@ -659,12 +659,7 @@ namespace boost {
           std::swap(buckets, other.buckets);
           std::swap(groups, other.groups);
 
-          bool b = boost::allocator_propagate_on_container_swap<
-            allocator_type>::type::value;
-          if (b) {
-            boost::core::invoke_swap(
-              get_node_allocator(), other.get_node_allocator());
-          }
+          swap_allocator_if_pocs(other);
         }
 
         node_allocator_type const& get_node_allocator() const
@@ -876,6 +871,27 @@ namespace boost {
           pbg->prev->next = pbg->next;
           pbg->prev = pbg->next = group_pointer();
         }
+
+        void swap_allocator_if_pocs(grouped_bucket_array& other)
+        {
+          using allocator_pocs =
+            typename boost::allocator_propagate_on_container_swap<
+              allocator_type>::type;
+          swap_allocator_if_pocs(
+            other, std::integral_constant<bool, allocator_pocs::value>());
+        }
+
+        void swap_allocator_if_pocs(
+          grouped_bucket_array& other, std::true_type /* propagate */)
+        {
+          boost::core::invoke_swap(
+            get_node_allocator(), other.get_node_allocator());
+        }
+
+        void swap_allocator_if_pocs(
+          grouped_bucket_array&, std::false_type /* don't propagate */)
+        {
+        }
       };
     } // namespace detail
   } // namespace unordered
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/concurrent_table.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/concurrent_table.hpp
index 218a78a412..66c257911a 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/concurrent_table.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/concurrent_table.hpp
@@ -469,6 +469,10 @@ class concurrent_table:
   using size_type=typename super::size_type;
   static constexpr std::size_t bulk_visit_size=16;
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+  using stats=typename super::stats;
+#endif
+
 private:
   template<typename Value,typename T>
   using enable_if_is_value_type=typename std::enable_if<
@@ -510,6 +514,7 @@ class concurrent_table:
     x.arrays=ah.release();
     x.size_ctrl.ml=x.initial_max_load();
     x.size_ctrl.size=0;
+    BOOST_UNORDERED_SWAP_STATS(this->cstats,x.cstats);
   }
 
   concurrent_table(compatible_nonconcurrent_table&& x):
@@ -965,6 +970,13 @@ class concurrent_table:
     super::reserve(n);
   }
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+  /* already thread safe */
+
+  using super::get_stats;
+  using super::reset_stats;
+#endif
+
   template<typename Predicate>
   friend std::size_t erase_if(concurrent_table& x,Predicate&& pr)
   {
@@ -1186,6 +1198,7 @@ class concurrent_table:
     GroupAccessMode access_mode,
     const Key& x,std::size_t pos0,std::size_t hash,F&& f)const
   {    
+    BOOST_UNORDERED_STATS_COUNTER(num_cmps);
     prober pb(pos0);
     do{
       auto pos=pb.get();
@@ -1197,19 +1210,27 @@ class concurrent_table:
         auto lck=access(access_mode,pos);
         do{
           auto n=unchecked_countr_zero(mask);
-          if(BOOST_LIKELY(
-            pg->is_occupied(n)&&bool(this->pred()(x,this->key_from(p[n]))))){
-            f(pg,n,p+n);
-            return 1;
+          if(BOOST_LIKELY(pg->is_occupied(n))){
+            BOOST_UNORDERED_INCREMENT_STATS_COUNTER(num_cmps);
+            if(BOOST_LIKELY(bool(this->pred()(x,this->key_from(p[n]))))){
+              f(pg,n,p+n);
+              BOOST_UNORDERED_ADD_STATS(
+                this->cstats.successful_lookup,(pb.length(),num_cmps));
+              return 1;
+            }
           }
           mask&=mask-1;
         }while(mask);
       }
       if(BOOST_LIKELY(pg->is_not_overflowed(hash))){
+        BOOST_UNORDERED_ADD_STATS(
+          this->cstats.unsuccessful_lookup,(pb.length(),num_cmps));
         return 0;
       }
     }
     while(BOOST_LIKELY(pb.next(this->arrays.groups_size_mask)));
+    BOOST_UNORDERED_ADD_STATS(
+      this->cstats.unsuccessful_lookup,(pb.length(),num_cmps));
     return 0;
   }
 
@@ -1244,6 +1265,7 @@ class concurrent_table:
 
     it=first;
     for(auto i=m;i--;++it){
+      BOOST_UNORDERED_STATS_COUNTER(num_cmps);
       auto          pos=positions[i];
       prober        pb(pos);
       auto          pg=this->arrays.groups()+pos;
@@ -1256,12 +1278,15 @@ class concurrent_table:
           auto lck=access(access_mode,pos);
           do{
             auto n=unchecked_countr_zero(mask);
-            if(BOOST_LIKELY(
-              pg->is_occupied(n)&&
-              bool(this->pred()(*it,this->key_from(p[n]))))){
-              f(cast_for(access_mode,type_policy::value_from(p[n])));
-              ++res;
-              goto next_key;
+            if(BOOST_LIKELY(pg->is_occupied(n))){
+              BOOST_UNORDERED_INCREMENT_STATS_COUNTER(num_cmps);
+              if(bool(this->pred()(*it,this->key_from(p[n])))){
+                f(cast_for(access_mode,type_policy::value_from(p[n])));
+                ++res;
+                BOOST_UNORDERED_ADD_STATS(
+                  this->cstats.successful_lookup,(pb.length(),num_cmps));
+                goto next_key;
+              }
             }
             mask&=mask-1;
           }while(mask);
@@ -1270,6 +1295,8 @@ class concurrent_table:
         do{
           if(BOOST_LIKELY(pg->is_not_overflowed(hashes[i]))||
              BOOST_UNLIKELY(!pb.next(this->arrays.groups_size_mask))){
+            BOOST_UNORDERED_ADD_STATS(
+              this->cstats.unsuccessful_lookup,(pb.length(),num_cmps));
             goto next_key;
           }
           pos=pb.get();
@@ -1490,6 +1517,7 @@ class concurrent_table:
             this->construct_element(p,std::forward<Args>(args)...);
             rslot.commit();
             rsize.commit();
+            BOOST_UNORDERED_ADD_STATS(this->cstats.insertion,(pb.length()));
             return 1;
           }
           pg->mark_overflow(hash);
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/core.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/core.hpp
index 9955ca1db3..e89a21cf94 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/core.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/core.hpp
@@ -40,6 +40,10 @@
 #include <type_traits>
 #include <utility>
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+#include <boost/unordered/detail/foa/cumulative_stats.hpp>
+#endif
+
 #if !defined(BOOST_UNORDERED_DISABLE_SSE2)
 #if defined(BOOST_UNORDERED_ENABLE_SSE2)|| \
     defined(__SSE2__)|| \
@@ -864,6 +868,7 @@ struct pow2_quadratic_prober
   pow2_quadratic_prober(std::size_t pos_):pos{pos_}{}
 
   inline std::size_t get()const{return pos;}
+  inline std::size_t length()const{return step+1;}
 
   /* next returns false when the whole array has been traversed, which ends
    * probing (in practice, full-table probing will only happen with very small
@@ -1125,6 +1130,54 @@ struct table_arrays
   value_type_pointer elements_;
 };
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+/* stats support */
+
+struct table_core_cumulative_stats
+{
+  concurrent_cumulative_stats<1> insertion;
+  concurrent_cumulative_stats<2> successful_lookup,
+                                 unsuccessful_lookup;
+};
+
+struct table_core_insertion_stats
+{
+  std::size_t            count;
+  sequence_stats_summary probe_length;
+};
+
+struct table_core_lookup_stats
+{
+  std::size_t            count;
+  sequence_stats_summary probe_length;
+  sequence_stats_summary num_comparisons;
+};
+
+struct table_core_stats
+{
+  table_core_insertion_stats insertion;
+  table_core_lookup_stats    successful_lookup,
+                             unsuccessful_lookup;
+};
+
+#define BOOST_UNORDERED_ADD_STATS(stats,args) stats.add args
+#define BOOST_UNORDERED_SWAP_STATS(stats1,stats2) std::swap(stats1,stats2)
+#define BOOST_UNORDERED_COPY_STATS(stats1,stats2) stats1=stats2
+#define BOOST_UNORDERED_RESET_STATS_OF(x) x.reset_stats()
+#define BOOST_UNORDERED_STATS_COUNTER(name) std::size_t name=0
+#define BOOST_UNORDERED_INCREMENT_STATS_COUNTER(name) ++name
+
+#else
+
+#define BOOST_UNORDERED_ADD_STATS(stats,args) ((void)0)
+#define BOOST_UNORDERED_SWAP_STATS(stats1,stats2) ((void)0)
+#define BOOST_UNORDERED_COPY_STATS(stats1,stats2) ((void)0)
+#define BOOST_UNORDERED_RESET_STATS_OF(x) ((void)0)
+#define BOOST_UNORDERED_STATS_COUNTER(name) ((void)0)
+#define BOOST_UNORDERED_INCREMENT_STATS_COUNTER(name) ((void)0)
+
+#endif
+
 struct if_constexpr_void_else{void operator()()const{}};
 
 template<bool B,typename F,typename G=if_constexpr_void_else>
@@ -1395,6 +1448,11 @@ table_core:empty_value<Hash,0>,empty_value<Pred,1>,empty_value<Allocator,2>
   using locator=table_locator<group_type,element_type>;
   using arrays_holder_type=arrays_holder<arrays_type,Allocator>;
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+  using cumulative_stats=table_core_cumulative_stats;
+  using stats=table_core_stats;
+#endif
+
   table_core(
     std::size_t n=default_bucket_count,const Hash& h_=Hash(),
     const Pred& pred_=Pred(),const Allocator& al_=Allocator()):
@@ -1429,6 +1487,7 @@ table_core:empty_value<Hash,0>,empty_value<Pred,1>,empty_value<Allocator,2>
     x.arrays=ah.release();
     x.size_ctrl.ml=x.initial_max_load();
     x.size_ctrl.size=0;
+    BOOST_UNORDERED_SWAP_STATS(cstats,x.cstats);
   }
 
   table_core(table_core&& x)
@@ -1454,11 +1513,13 @@ table_core:empty_value<Hash,0>,empty_value<Pred,1>,empty_value<Allocator,2>
       using std::swap;
       swap(arrays,x.arrays);
       swap(size_ctrl,x.size_ctrl);
+      BOOST_UNORDERED_SWAP_STATS(cstats,x.cstats);
     }
     else{
       reserve(x.size());
       clear_on_exit c{x};
       (void)c; /* unused var warning */
+      BOOST_UNORDERED_RESET_STATS_OF(x);
 
       /* This works because subsequent x.clear() does not depend on the
        * elements' values.
@@ -1574,9 +1635,11 @@ table_core:empty_value<Hash,0>,empty_value<Pred,1>,empty_value<Allocator,2>
         arrays=x.arrays;
         size_ctrl.ml=std::size_t(x.size_ctrl.ml);
         size_ctrl.size=std::size_t(x.size_ctrl.size);
+        BOOST_UNORDERED_COPY_STATS(cstats,x.cstats);
         x.arrays=ah.release();
         x.size_ctrl.ml=x.initial_max_load();
         x.size_ctrl.size=0;
+        BOOST_UNORDERED_RESET_STATS_OF(x);
       }
       else{
         swap(h(),x.h());
@@ -1586,6 +1649,7 @@ table_core:empty_value<Hash,0>,empty_value<Pred,1>,empty_value<Allocator,2>
         noshrink_reserve(x.size());
         clear_on_exit c{x};
         (void)c; /* unused var warning */
+        BOOST_UNORDERED_RESET_STATS_OF(x);
 
         /* This works because subsequent x.clear() does not depend on the
          * elements' values.
@@ -1639,6 +1703,7 @@ table_core:empty_value<Hash,0>,empty_value<Pred,1>,empty_value<Allocator,2>
   BOOST_FORCEINLINE locator find(
     const Key& x,std::size_t pos0,std::size_t hash)const
   {    
+    BOOST_UNORDERED_STATS_COUNTER(num_cmps);
     prober pb(pos0);
     do{
       auto pos=pb.get();
@@ -1650,18 +1715,25 @@ table_core:empty_value<Hash,0>,empty_value<Pred,1>,empty_value<Allocator,2>
         auto p=elements+pos*N;
         BOOST_UNORDERED_PREFETCH_ELEMENTS(p,N);
         do{
+          BOOST_UNORDERED_INCREMENT_STATS_COUNTER(num_cmps);
           auto n=unchecked_countr_zero(mask);
           if(BOOST_LIKELY(bool(pred()(x,key_from(p[n]))))){
+            BOOST_UNORDERED_ADD_STATS(
+              cstats.successful_lookup,(pb.length(),num_cmps));
             return {pg,n,p+n};
           }
           mask&=mask-1;
         }while(mask);
       }
       if(BOOST_LIKELY(pg->is_not_overflowed(hash))){
+        BOOST_UNORDERED_ADD_STATS(
+          cstats.unsuccessful_lookup,(pb.length(),num_cmps));
         return {};
       }
     }
     while(BOOST_LIKELY(pb.next(arrays.groups_size_mask)));
+    BOOST_UNORDERED_ADD_STATS(
+      cstats.unsuccessful_lookup,(pb.length(),num_cmps));
     return {};
   }
 
@@ -1746,6 +1818,38 @@ table_core:empty_value<Hash,0>,empty_value<Pred,1>,empty_value<Allocator,2>
     rehash(std::size_t(std::ceil(float(n)/mlf)));
   }
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+  stats get_stats()const
+  {
+    auto insertion=cstats.insertion.get_summary();
+    auto successful_lookup=cstats.successful_lookup.get_summary();
+    auto unsuccessful_lookup=cstats.unsuccessful_lookup.get_summary();
+    return{
+      {
+        insertion.count,
+        insertion.sequence_summary[0]
+      },
+      {
+        successful_lookup.count,
+        successful_lookup.sequence_summary[0],
+        successful_lookup.sequence_summary[1]
+      },
+      {
+        unsuccessful_lookup.count,
+        unsuccessful_lookup.sequence_summary[0],
+        unsuccessful_lookup.sequence_summary[1]
+      },
+    };
+  }
+
+  void reset_stats()noexcept
+  {
+    cstats.insertion.reset();
+    cstats.successful_lookup.reset();
+    cstats.unsuccessful_lookup.reset();
+  }
+#endif
+
   friend bool operator==(const table_core& x,const table_core& y)
   {
     return
@@ -1953,8 +2057,12 @@ table_core:empty_value<Hash,0>,empty_value<Pred,1>,empty_value<Allocator,2>
     return true;
   }
 
-  arrays_type    arrays;
-  size_ctrl_type size_ctrl;
+  arrays_type              arrays;
+  size_ctrl_type           size_ctrl;
+
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+  mutable cumulative_stats cstats;
+#endif
 
 private:
   template<
@@ -2243,6 +2351,7 @@ table_core:empty_value<Hash,0>,empty_value<Pred,1>,empty_value<Allocator,2>
         auto p=arrays_.elements()+pos*N+n;
         construct_element(p,std::forward<Args>(args)...);
         pg->set(n,hash);
+        BOOST_UNORDERED_ADD_STATS(cstats.insertion,(pb.length()));
         return {pg,n,p};
       }
       else pg->mark_overflow(hash);
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/cumulative_stats.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/cumulative_stats.hpp
new file mode 100644
index 0000000000..13a157474f
--- /dev/null
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/cumulative_stats.hpp
@@ -0,0 +1,177 @@
+/* Copyright 2024 Joaquin M Lopez Munoz.
+ * Distributed under the Boost Software License, Version 1.0.
+ * (See accompanying file LICENSE_1_0.txt or copy at
+ * http://www.boost.org/LICENSE_1_0.txt)
+ *
+ * See https://www.boost.org/libs/unordered for library home page.
+ */
+
+#ifndef BOOST_UNORDERED_DETAIL_FOA_CUMULATIVE_STATS_HPP
+#define BOOST_UNORDERED_DETAIL_FOA_CUMULATIVE_STATS_HPP
+
+#include <array>
+#include <boost/config.hpp>
+#include <boost/mp11/tuple.hpp>
+#include <cmath>
+#include <cstddef>
+
+#if defined(BOOST_HAS_THREADS)
+#include <boost/unordered/detail/foa/rw_spinlock.hpp>
+#include <mutex>
+#endif
+
+namespace boost{
+namespace unordered{
+namespace detail{
+namespace foa{
+
+/* Cumulative one-pass calculation of the average, variance and deviation of
+ * running sequences.
+ */
+
+struct sequence_stats_data
+{
+  double m=0.0;
+  double m_prior=0.0;
+  double s=0.0;
+};
+
+struct welfords_algorithm /* 0-based */
+{
+  template<typename T>
+  int operator()(T&& x,sequence_stats_data& d)const noexcept
+  {
+    static_assert(
+      noexcept(static_cast<double>(x)),
+      "Argument conversion to double must not throw.");
+
+    d.m_prior=d.m;
+    d.m+=(static_cast<double>(x)-d.m)/static_cast<double>(n);
+    d.s+=(n!=1)*
+      (static_cast<double>(x)-d.m_prior)*(static_cast<double>(x)-d.m);
+
+    return 0; /* mp11::tuple_transform requires that return type not be void */
+  }
+
+  std::size_t n;
+};
+
+struct sequence_stats_summary
+{
+  double average;
+  double variance;
+  double deviation;
+};
+
+/* Stats calculated jointly for N same-sized sequences to save the space
+ * for count.
+ */
+
+template<std::size_t N>
+class cumulative_stats
+{
+public:
+  struct summary
+  {
+    std::size_t                          count;
+    std::array<sequence_stats_summary,N> sequence_summary;
+  };
+
+  void reset()noexcept{*this=cumulative_stats();}
+  
+  template<typename... Ts>
+  void add(Ts&&... xs)noexcept
+  {
+    static_assert(
+      sizeof...(Ts)==N,"A sample must be provided for each sequence.");
+
+    if(BOOST_UNLIKELY(++n==0)){ /* wraparound */
+      reset();
+      n=1;
+    }
+    mp11::tuple_transform(
+      welfords_algorithm{n},
+      std::forward_as_tuple(std::forward<Ts>(xs)...),
+      data);
+  }
+  
+  summary get_summary()const noexcept
+  {
+    summary res;
+    res.count=n;
+    for(std::size_t i=0;i<N;++i){
+      double average=data[i].m,
+             variance=n!=0?data[i].s/static_cast<double>(n):0.0, /* biased */
+             deviation=std::sqrt(variance);
+      res.sequence_summary[i]={average,variance,deviation};
+    }
+    return res;
+  }
+
+private:
+  std::size_t                       n=0;
+  std::array<sequence_stats_data,N> data;
+};
+
+#if defined(BOOST_HAS_THREADS)
+
+template<std::size_t N>
+class concurrent_cumulative_stats:cumulative_stats<N>
+{
+  using super=cumulative_stats<N>;
+  using lock_guard=std::lock_guard<rw_spinlock>;
+
+public:
+  using summary=typename super::summary;
+
+  concurrent_cumulative_stats()noexcept:super{}{}
+  concurrent_cumulative_stats(const concurrent_cumulative_stats& x)noexcept:
+    concurrent_cumulative_stats{x,lock_guard{x.mut}}{}
+
+  concurrent_cumulative_stats&
+  operator=(const concurrent_cumulative_stats& x)noexcept
+  {
+    auto x1=x;
+    lock_guard lck{mut};
+    static_cast<super&>(*this)=x1;
+    return *this;
+  }
+
+  void reset()noexcept
+  {
+    lock_guard lck{mut};
+    super::reset();
+  }
+  
+  template<typename... Ts>
+  void add(Ts&&... xs)noexcept
+  {
+    lock_guard lck{mut};
+    super::add(std::forward<Ts>(xs)...);
+  }
+  
+  summary get_summary()const noexcept
+  {
+    lock_guard lck{mut};
+    return super::get_summary();
+  }
+
+private:
+  concurrent_cumulative_stats(const super& x,lock_guard&&):super{x}{}
+
+  mutable rw_spinlock mut;
+};
+
+#else
+
+template<std::size_t N>
+using concurrent_cumulative_stats=cumulative_stats<N>;
+
+#endif
+
+} /* namespace foa */
+} /* namespace detail */
+} /* namespace unordered */
+} /* namespace boost */
+
+#endif
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/table.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/table.hpp
index 87aa049584..529a514cd0 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/table.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/detail/foa/table.hpp
@@ -1,6 +1,6 @@
 /* Fast open-addressing hash table.
  *
- * Copyright 2022-2023 Joaquin M Lopez Munoz.
+ * Copyright 2022-2024 Joaquin M Lopez Munoz.
  * Copyright 2023 Christian Mazakas.
  * Copyright 2024 Braden Ganetsky.
  * Distributed under the Boost Software License, Version 1.0.
@@ -361,6 +361,10 @@ class table:table_core_impl<TypePolicy,Hash,Pred,Allocator>
     const_iterator>::type;
   using erase_return_type=table_erase_return_type<iterator>;
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+  using stats=typename super::stats;
+#endif
+
   table(
     std::size_t n=default_bucket_count,const Hash& h_=Hash(),
     const Pred& pred_=Pred(),const Allocator& al_=Allocator()):
@@ -542,6 +546,11 @@ class table:table_core_impl<TypePolicy,Hash,Pred,Allocator>
   using super::rehash;
   using super::reserve;
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+  using super::get_stats;
+  using super::reset_stats;
+#endif
+
   template<typename Predicate>
   friend std::size_t erase_if(table& x,Predicate& pr)
   {
@@ -584,6 +593,7 @@ class table:table_core_impl<TypePolicy,Hash,Pred,Allocator>
     x.arrays=ah.release();
     x.size_ctrl.ml=x.initial_max_load();
     x.size_ctrl.size=0;
+    BOOST_UNORDERED_SWAP_STATS(this->cstats,x.cstats);
   }
 
   template<typename ExclusiveLockGuard>
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/hash_traits.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/hash_traits.hpp
index d5f94a7898..5e2b1af05a 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/hash_traits.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/hash_traits.hpp
@@ -1,6 +1,6 @@
 /* Hash function characterization.
  *
- * Copyright 2022 Joaquin M Lopez Munoz.
+ * Copyright 2022-2024 Joaquin M Lopez Munoz.
  * Distributed under the Boost Software License, Version 1.0.
  * (See accompanying file LICENSE_1_0.txt or copy at
  * http://www.boost.org/LICENSE_1_0.txt)
@@ -19,12 +19,34 @@ namespace unordered{
 namespace detail{
 
 template<typename Hash,typename=void>
-struct hash_is_avalanching_impl: std::false_type{};
+struct hash_is_avalanching_impl:std::false_type{};
+
+template<typename IsAvalanching>
+struct avalanching_value
+{
+  static constexpr bool value=IsAvalanching::value;
+};
+
+/* may be explicitly marked as BOOST_DEPRECATED in the future */
+template<> struct avalanching_value<void>
+{
+  static constexpr bool value=true;
+};
+
+template<typename Hash>
+struct hash_is_avalanching_impl<
+  Hash,
+  boost::unordered::detail::void_t<typename Hash::is_avalanching>
+>:std::integral_constant<
+  bool,
+  avalanching_value<typename Hash::is_avalanching>::value
+>{};
 
 template<typename Hash>
-struct hash_is_avalanching_impl<Hash,
-  boost::unordered::detail::void_t<typename Hash::is_avalanching> >:
-    std::true_type{};
+struct hash_is_avalanching_impl<
+  Hash,
+  typename std::enable_if<((void)Hash::is_avalanching,true)>::type
+>{}; /* Hash::is_avalanching is not a type: compile error downstream */
 
 } /* namespace detail */
 
@@ -32,8 +54,12 @@ struct hash_is_avalanching_impl<Hash,
  * when actual characterization differs from default.
  */
 
-/* hash_is_avalanching<Hash>::value is true when the type Hash::is_avalanching
- * is present, false otherwise.
+/* hash_is_avalanching<Hash>::value is:
+ *   - false if Hash::is_avalanching is not present.
+ *   - Hash::is_avalanching::value if this is present and constexpr-convertible
+ *     to a bool.
+ *   - true if Hash::is_avalanching is void (deprecated).
+ *   - ill-formed otherwise.
  */
 template<typename Hash>
 struct hash_is_avalanching: detail::hash_is_avalanching_impl<Hash>::type{};
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_map.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_map.hpp
index 41ce70813e..5502410297 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_map.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_map.hpp
@@ -76,6 +76,10 @@ namespace boost {
       using iterator = typename table_type::iterator;
       using const_iterator = typename table_type::const_iterator;
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+      using stats = typename table_type::stats;
+#endif
+
       unordered_flat_map() : unordered_flat_map(0) {}
 
       explicit unordered_flat_map(size_type n, hasher const& h = hasher(),
@@ -654,6 +658,14 @@ namespace boost {
 
       void reserve(size_type n) { table_.reserve(n); }
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+      /// Stats
+      ///
+      stats get_stats() const { return table_.get_stats(); }
+
+      void reset_stats() noexcept { table_.reset_stats(); }
+#endif
+
       /// Observers
       ///
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_map_fwd.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_map_fwd.hpp
index 5551d1a6e4..f758f83a08 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_map_fwd.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_map_fwd.hpp
@@ -1,5 +1,6 @@
 
 // Copyright (C) 2022 Christian Mazakas
+// Copyright (C) 2024 Braden Ganetsky
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
@@ -15,6 +16,10 @@
 #include <functional>
 #include <memory>
 
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+#include <memory_resource>
+#endif
+
 namespace boost {
   namespace unordered {
     template <class Key, class T, class Hash = boost::hash<Key>,
@@ -36,6 +41,16 @@ namespace boost {
     void swap(unordered_flat_map<Key, T, Hash, KeyEqual, Allocator>& lhs,
       unordered_flat_map<Key, T, Hash, KeyEqual, Allocator>& rhs)
       noexcept(noexcept(lhs.swap(rhs)));
+
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+    namespace pmr {
+      template <class Key, class T, class Hash = boost::hash<Key>,
+        class KeyEqual = std::equal_to<Key> >
+      using unordered_flat_map =
+        boost::unordered::unordered_flat_map<Key, T, Hash, KeyEqual,
+          std::pmr::polymorphic_allocator<std::pair<const Key, T> > >;
+    } // namespace pmr
+#endif
   } // namespace unordered
 
   using boost::unordered::unordered_flat_map;
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_set.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_set.hpp
index a6aba397ca..a72d356701 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_set.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_set.hpp
@@ -72,6 +72,10 @@ namespace boost {
       using iterator = typename table_type::iterator;
       using const_iterator = typename table_type::const_iterator;
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+      using stats = typename table_type::stats;
+#endif
+
       unordered_flat_set() : unordered_flat_set(0) {}
 
       explicit unordered_flat_set(size_type n, hasher const& h = hasher(),
@@ -474,6 +478,14 @@ namespace boost {
 
       void reserve(size_type n) { table_.reserve(n); }
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+      /// Stats
+      ///
+      stats get_stats() const { return table_.get_stats(); }
+
+      void reset_stats() noexcept { table_.reset_stats(); }
+#endif
+
       /// Observers
       ///
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_set_fwd.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_set_fwd.hpp
index 02435bab45..9214939fc3 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_set_fwd.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_flat_set_fwd.hpp
@@ -1,5 +1,6 @@
 
 // Copyright (C) 2022 Christian Mazakas
+// Copyright (C) 2024 Braden Ganetsky
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
@@ -15,6 +16,10 @@
 #include <functional>
 #include <memory>
 
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+#include <memory_resource>
+#endif
+
 namespace boost {
   namespace unordered {
     template <class Key, class Hash = boost::hash<Key>,
@@ -36,6 +41,15 @@ namespace boost {
     void swap(unordered_flat_set<Key, Hash, KeyEqual, Allocator>& lhs,
       unordered_flat_set<Key, Hash, KeyEqual, Allocator>& rhs)
       noexcept(noexcept(lhs.swap(rhs)));
+
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+    namespace pmr {
+      template <class Key, class Hash = boost::hash<Key>,
+        class KeyEqual = std::equal_to<Key> >
+      using unordered_flat_set = boost::unordered::unordered_flat_set<Key, Hash,
+        KeyEqual, std::pmr::polymorphic_allocator<Key> >;
+    } // namespace pmr
+#endif
   } // namespace unordered
 
   using boost::unordered::unordered_flat_set;
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_map_fwd.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_map_fwd.hpp
index b374965e01..375889a1c8 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_map_fwd.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_map_fwd.hpp
@@ -1,6 +1,7 @@
 
 // Copyright (C) 2008-2011 Daniel James.
 // Copyright (C) 2022-2023 Christian Mazakas
+// Copyright (C) 2024 Braden Ganetsky
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
@@ -16,6 +17,10 @@
 #include <functional>
 #include <memory>
 
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+#include <memory_resource>
+#endif
+
 namespace boost {
   namespace unordered {
     template <class K, class T, class H = boost::hash<K>,
@@ -58,6 +63,20 @@ namespace boost {
 
     template <class N, class K, class T, class A> class node_handle_map;
     template <class Iter, class NodeType> struct insert_return_type_map;
+
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+    namespace pmr {
+      template <class K, class T, class H = boost::hash<K>,
+        class P = std::equal_to<K> >
+      using unordered_map = boost::unordered::unordered_map<K, T, H, P,
+        std::pmr::polymorphic_allocator<std::pair<const K, T> > >;
+
+      template <class K, class T, class H = boost::hash<K>,
+        class P = std::equal_to<K> >
+      using unordered_multimap = boost::unordered::unordered_multimap<K, T, H,
+        P, std::pmr::polymorphic_allocator<std::pair<const K, T> > >;
+    } // namespace pmr
+#endif
   } // namespace unordered
 
   using boost::unordered::unordered_map;
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_map.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_map.hpp
index b7a6a4095c..def251fa81 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_map.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_map.hpp
@@ -115,6 +115,10 @@ namespace boost {
       using insert_return_type =
         detail::foa::insert_return_type<iterator, node_type>;
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+      using stats = typename table_type::stats;
+#endif
+
       unordered_node_map() : unordered_node_map(0) {}
 
       explicit unordered_node_map(size_type n, hasher const& h = hasher(),
@@ -749,6 +753,14 @@ namespace boost {
 
       void reserve(size_type n) { table_.reserve(n); }
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+      /// Stats
+      ///
+      stats get_stats() const { return table_.get_stats(); }
+
+      void reset_stats() noexcept { table_.reset_stats(); }
+#endif
+
       /// Observers
       ///
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_map_fwd.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_map_fwd.hpp
index ec598168b9..95ac162da2 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_map_fwd.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_map_fwd.hpp
@@ -1,5 +1,6 @@
 
 // Copyright (C) 2022 Christian Mazakas
+// Copyright (C) 2024 Braden Ganetsky
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
@@ -15,6 +16,10 @@
 #include <functional>
 #include <memory>
 
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+#include <memory_resource>
+#endif
+
 namespace boost {
   namespace unordered {
     template <class Key, class T, class Hash = boost::hash<Key>,
@@ -36,6 +41,16 @@ namespace boost {
     void swap(unordered_node_map<Key, T, Hash, KeyEqual, Allocator>& lhs,
       unordered_node_map<Key, T, Hash, KeyEqual, Allocator>& rhs)
       noexcept(noexcept(lhs.swap(rhs)));
+
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+    namespace pmr {
+      template <class Key, class T, class Hash = boost::hash<Key>,
+        class KeyEqual = std::equal_to<Key> >
+      using unordered_node_map =
+        boost::unordered::unordered_node_map<Key, T, Hash, KeyEqual,
+          std::pmr::polymorphic_allocator<std::pair<const Key, T> > >;
+    } // namespace pmr
+#endif
   } // namespace unordered
 
   using boost::unordered::unordered_node_map;
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_set.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_set.hpp
index 14b44bed0c..e5e14115f9 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_set.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_set.hpp
@@ -105,6 +105,10 @@ namespace boost {
       using insert_return_type =
         detail::foa::insert_return_type<iterator, node_type>;
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+      using stats = typename table_type::stats;
+#endif
+
       unordered_node_set() : unordered_node_set(0) {}
 
       explicit unordered_node_set(size_type n, hasher const& h = hasher(),
@@ -563,6 +567,14 @@ namespace boost {
 
       void reserve(size_type n) { table_.reserve(n); }
 
+#if defined(BOOST_UNORDERED_ENABLE_STATS)
+      /// Stats
+      ///
+      stats get_stats() const { return table_.get_stats(); }
+
+      void reset_stats() noexcept { table_.reset_stats(); }
+#endif
+
       /// Observers
       ///
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_set_fwd.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_set_fwd.hpp
index 977d032fd8..75215f2ae0 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_set_fwd.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_node_set_fwd.hpp
@@ -1,5 +1,6 @@
 
 // Copyright (C) 2023 Christian Mazakas
+// Copyright (C) 2024 Braden Ganetsky
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
@@ -15,6 +16,10 @@
 #include <functional>
 #include <memory>
 
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+#include <memory_resource>
+#endif
+
 namespace boost {
   namespace unordered {
     template <class Key, class Hash = boost::hash<Key>,
@@ -36,6 +41,15 @@ namespace boost {
     void swap(unordered_node_set<Key, Hash, KeyEqual, Allocator>& lhs,
       unordered_node_set<Key, Hash, KeyEqual, Allocator>& rhs)
       noexcept(noexcept(lhs.swap(rhs)));
+
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+    namespace pmr {
+      template <class Key, class Hash = boost::hash<Key>,
+        class KeyEqual = std::equal_to<Key> >
+      using unordered_node_set = boost::unordered::unordered_node_set<Key, Hash,
+        KeyEqual, std::pmr::polymorphic_allocator<Key> >;
+    } // namespace pmr
+#endif
   } // namespace unordered
 
   using boost::unordered::unordered_node_set;
diff --git a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_set_fwd.hpp b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_set_fwd.hpp
index b74c613686..aea95d8829 100644
--- a/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_set_fwd.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/unordered/unordered_set_fwd.hpp
@@ -1,6 +1,7 @@
 
 // Copyright (C) 2008-2011 Daniel James.
 // Copyright (C) 2022 Christian Mazakas
+// Copyright (C) 2024 Braden Ganetsky
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
@@ -16,6 +17,10 @@
 #include <functional>
 #include <memory>
 
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+#include <memory_resource>
+#endif
+
 namespace boost {
   namespace unordered {
     template <class T, class H = boost::hash<T>, class P = std::equal_to<T>,
@@ -56,6 +61,18 @@ namespace boost {
 
     template <class N, class T, class A> class node_handle_set;
     template <class Iter, class NodeType> struct insert_return_type_set;
+
+#ifndef BOOST_NO_CXX17_HDR_MEMORY_RESOURCE
+    namespace pmr {
+      template <class T, class H = boost::hash<T>, class P = std::equal_to<T> >
+      using unordered_set = boost::unordered::unordered_set<T, H, P,
+        std::pmr::polymorphic_allocator<T> >;
+
+      template <class T, class H = boost::hash<T>, class P = std::equal_to<T> >
+      using unordered_multiset = boost::unordered::unordered_multiset<T, H, P,
+        std::pmr::polymorphic_allocator<T> >;
+    } // namespace pmr
+#endif
   } // namespace unordered
 
   using boost::unordered::unordered_multiset;
diff --git a/src/cxx_supportlib/vendor-modified/boost/utility/detail/minstd_rand.hpp b/src/cxx_supportlib/vendor-modified/boost/utility/detail/minstd_rand.hpp
index 95efb21a32..a13614bb06 100644
--- a/src/cxx_supportlib/vendor-modified/boost/utility/detail/minstd_rand.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/utility/detail/minstd_rand.hpp
@@ -11,48 +11,6 @@
 // An implementation of minstd_rand that does not require
 // the Random library
 
-#include <boost/cstdint.hpp>
-
-namespace boost
-{
-namespace detail
-{
-
-class minstd_rand
-{
-private:
-
-    boost::uint_least32_t x_;
-
-    enum { a = 48271, m = 2147483647 };
-
-public:
-
-    minstd_rand(): x_( 1 )
-    {
-    }
-
-    explicit minstd_rand( boost::uint_least32_t x ): x_( x % m )
-    {
-        if( x_ == 0 )
-        {
-            x_ = 1;
-        }
-    }
-
-    boost::uint_least32_t operator()()
-    {
-        boost::uint_least64_t y = x_;
-
-        y = ( a * y ) % m;
-
-        x_ = static_cast<boost::uint_least32_t>( y );
-
-        return x_;
-    }
-};
-
-} // namespace detail
-} // namespace boost
+#include <boost/core/detail/minstd_rand.hpp>
 
 #endif // #ifndef BOOST_UTILITY_DETAIL_MINSTD_RAND_HPP_INCLUDED
diff --git a/src/cxx_supportlib/vendor-modified/boost/version.hpp b/src/cxx_supportlib/vendor-modified/boost/version.hpp
index 989f25fa37..a8466b643b 100644
--- a/src/cxx_supportlib/vendor-modified/boost/version.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/version.hpp
@@ -19,7 +19,7 @@
 //  BOOST_VERSION / 100 % 1000 is the minor version
 //  BOOST_VERSION / 100000 is the major version
 
-#define BOOST_VERSION 108500
+#define BOOST_VERSION 108600
 
 //
 //  BOOST_LIB_VERSION must be defined to be the same as BOOST_VERSION
@@ -27,6 +27,6 @@
 //  number, y is the minor version number, and z is the patch level if not 0.
 //  This is used by <config/auto_link.hpp> to select which library version to link to.
 
-#define BOOST_LIB_VERSION "1_85"
+#define BOOST_LIB_VERSION "1_86"
 
 #endif

From 5272cfaa572cd5b847587a766ff6648234a4bc7e Mon Sep 17 00:00:00 2001
From: Camden Narzt <c.narzt@me.com>
Date: Mon, 9 Sep 2024 15:38:35 -0600
Subject: [PATCH 03/16] patch boost

---
 src/cxx_supportlib/vendor-modified/boost/asio.hpp        | 9 ---------
 .../vendor-modified/boost/thread/detail/thread.hpp       | 4 ++--
 .../vendor-modified/boost/thread/exceptions.hpp          | 2 ++
 src/cxx_supportlib/vendor-modified/boost/thread/once.hpp | 2 +-
 4 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/src/cxx_supportlib/vendor-modified/boost/asio.hpp b/src/cxx_supportlib/vendor-modified/boost/asio.hpp
index 09efee9d6a..947f0d8bab 100644
--- a/src/cxx_supportlib/vendor-modified/boost/asio.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/asio.hpp
@@ -188,15 +188,6 @@
 #include <boost/asio/uses_executor.hpp>
 #include <boost/asio/version.hpp>
 #include <boost/asio/wait_traits.hpp>
-#include <boost/asio/windows/basic_object_handle.hpp>
-#include <boost/asio/windows/basic_overlapped_handle.hpp>
-#include <boost/asio/windows/basic_random_access_handle.hpp>
-#include <boost/asio/windows/basic_stream_handle.hpp>
-#include <boost/asio/windows/object_handle.hpp>
-#include <boost/asio/windows/overlapped_handle.hpp>
-#include <boost/asio/windows/overlapped_ptr.hpp>
-#include <boost/asio/windows/random_access_handle.hpp>
-#include <boost/asio/windows/stream_handle.hpp>
 #include <boost/asio/writable_pipe.hpp>
 #include <boost/asio/write.hpp>
 #include <boost/asio/write_at.hpp>
diff --git a/src/cxx_supportlib/vendor-modified/boost/thread/detail/thread.hpp b/src/cxx_supportlib/vendor-modified/boost/thread/detail/thread.hpp
index 3717311060..ffcb728264 100644
--- a/src/cxx_supportlib/vendor-modified/boost/thread/detail/thread.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/thread/detail/thread.hpp
@@ -166,7 +166,7 @@ namespace boost
       typedef thread_attributes attributes;
 
       BOOST_THREAD_MOVABLE_ONLY(thread)
-    private:
+    protected:
 
         struct dummy;
 
@@ -174,7 +174,7 @@ namespace boost
 
         detail::thread_data_ptr thread_info;
 
-    private:
+    protected:
         bool start_thread_noexcept();
         bool start_thread_noexcept(const attributes& attr);
         void start_thread()
diff --git a/src/cxx_supportlib/vendor-modified/boost/thread/exceptions.hpp b/src/cxx_supportlib/vendor-modified/boost/thread/exceptions.hpp
index 2a5094bd5a..5c2d9cb853 100644
--- a/src/cxx_supportlib/vendor-modified/boost/thread/exceptions.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/thread/exceptions.hpp
@@ -21,6 +21,7 @@
 #include <stdexcept>
 #include <boost/system/system_error.hpp>
 #include <boost/system/error_code.hpp>
+#include <oxt/tracable_exception.hpp>
 
 
 #include <boost/config/abi_prefix.hpp>
@@ -30,6 +31,7 @@ namespace boost
 
 #if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
     class BOOST_SYMBOL_VISIBLE thread_interrupted
+      : public oxt::tracable_exception
     {};
 #endif
 
diff --git a/src/cxx_supportlib/vendor-modified/boost/thread/once.hpp b/src/cxx_supportlib/vendor-modified/boost/thread/once.hpp
index 22f95139ae..d458fb5314 100644
--- a/src/cxx_supportlib/vendor-modified/boost/thread/once.hpp
+++ b/src/cxx_supportlib/vendor-modified/boost/thread/once.hpp
@@ -38,7 +38,7 @@ namespace boost
   // template<class Callable, class ...Args> void
   // call_once(once_flag& flag, Callable&& func, Args&&... args);
 template<typename Function>
-inline void call_once(Function func,once_flag& flag)
+inline void call_once(Function func,boost::once_flag& flag)
 //inline void call_once(void (*func)(),once_flag& flag)
     {
         call_once(flag,func);

From 3fe31a7d75f5ec34fd602b6b5951fdd6a40238cf Mon Sep 17 00:00:00 2001
From: Hongli Lai <hongli@phusion.nl>
Date: Tue, 17 Sep 2024 17:03:09 +0200
Subject: [PATCH 04/16] Use ARM64 runners for Github Action

---
 .github/workflows/binaries.yml | 21 ++++++++-------------
 .github/workflows/main.yml     | 10 ++--------
 2 files changed, 10 insertions(+), 21 deletions(-)

diff --git a/.github/workflows/binaries.yml b/.github/workflows/binaries.yml
index 8af3b2d84e..7ef2fda0ba 100644
--- a/.github/workflows/binaries.yml
+++ b/.github/workflows/binaries.yml
@@ -4,14 +4,8 @@ env:
   ENTERPRISE: 0
 
 on:
-  push:
-    branches:
-      - 'stable-*'
-      - 'feature/*'
-  pull_request:
-    branches:
-      - 'stable-*'
-      - 'feature/*'
+  push: {}
+  pull_request: {}
 
 jobs:
   build_linux:
@@ -19,10 +13,12 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        arch:
-          - x86_64
-          - aarch64
-    runs-on: ubuntu-latest
+        include:
+          - arch: x86_64
+            runner: ubuntu-24.04
+          - arch: aarch64
+            runner: passenger-ubuntu-24.04-arm64-2cpu
+    runs-on: ${{ matrix.runner }}
     env:
       WORKSPACE: ${{ github.workspace }}
       OUTPUT_DIR: ${{ github.workspace }}/output-linux-${{ matrix.arch }}
@@ -33,7 +29,6 @@ jobs:
     - uses: actions/checkout@v4
       with:
         submodules: true
-    - uses: docker/setup-qemu-action@v3
     - uses: docker/setup-buildx-action@v3
     - run: ./dev/ci/tests/binaries/build-linux
     - uses: actions/upload-artifact@v4
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 8813b966a4..b52d0ae2d6 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -5,14 +5,8 @@ env:
   COMPILE_CONCURRENCY: 4
 
 on:
-  push:
-    branches:
-      - 'stable-*'
-      - 'feature/*'
-  pull_request:
-    branches:
-      - 'stable-*'
-      - 'feature/*'
+  push: {}
+  pull_request: {}
 
 jobs:
   cxx:

From a02e9c89942739336304590d3596634e9e13b948 Mon Sep 17 00:00:00 2001
From: Camden Narzt <c.narzt@me.com>
Date: Sun, 29 Sep 2024 12:49:40 -0600
Subject: [PATCH 05/16] add test for endsWith

---
 test/cxx/StrIntTools/StrIntUtilsTest.cpp | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/test/cxx/StrIntTools/StrIntUtilsTest.cpp b/test/cxx/StrIntTools/StrIntUtilsTest.cpp
index ae8523e5c2..c22e647b8b 100644
--- a/test/cxx/StrIntTools/StrIntUtilsTest.cpp
+++ b/test/cxx/StrIntTools/StrIntUtilsTest.cpp
@@ -48,4 +48,13 @@ namespace tut {
 		string result = escapeHTML(s);
 		ensure_equals(result, "h?llo");
 	}
+
+	TEST_METHOD(5) {
+		set_test_name("endsWith works");
+		char* str1 = "abcdefghijklmnopqrstuvwxyz";
+		ensure(endsWith(str1, "xyz"));
+		ensure(endsWith("xyz", "xyz"));
+		ensure(!endsWith(str1, "zzz"));
+		ensure(!endsWith("xyz", "zzz"));
+	}
 }

From 7397933147c739dc1237af1459b3a2aa8d309492 Mon Sep 17 00:00:00 2001
From: Camden Narzt <c.narzt@me.com>
Date: Sun, 29 Sep 2024 12:49:25 -0600
Subject: [PATCH 06/16] remove unused include

---
 src/cxx_supportlib/ServerKit/HttpHeaderParser.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/cxx_supportlib/ServerKit/HttpHeaderParser.h b/src/cxx_supportlib/ServerKit/HttpHeaderParser.h
index ee6b4e2d48..494437f41f 100644
--- a/src/cxx_supportlib/ServerKit/HttpHeaderParser.h
+++ b/src/cxx_supportlib/ServerKit/HttpHeaderParser.h
@@ -29,7 +29,6 @@
 #include <boost/cstdint.hpp>
 #include <oxt/backtrace.hpp>
 #include <cstddef>
-#include <cassert>
 #include <cstring>
 #include <MemoryKit/mbuf.h>
 #include <ServerKit/llhttp.h>

From 01bfa8c754e7a1e3cae41bd9fe7a9057518d8935 Mon Sep 17 00:00:00 2001
From: Camden Narzt <c.narzt@me.com>
Date: Mon, 30 Sep 2024 10:55:32 -0600
Subject: [PATCH 07/16] try to fix jenkins compat with GHA

since migration is going slow
---
 dev/ci/lib/functions.sh               | 35 ++++++++++++++++++------
 dev/ci/lib/set-container-envvars.sh   | 38 +++++++++++++++++----------
 dev/ci/lib/setup-container.sh         |  9 ++++++-
 dev/ci/setup-host                     |  5 ++--
 dev/ci/tests/homebrew-packaging/setup | 19 +++++++++++---
 5 files changed, 78 insertions(+), 28 deletions(-)

diff --git a/dev/ci/lib/functions.sh b/dev/ci/lib/functions.sh
index 58adfd670d..8acb4ad3df 100644
--- a/dev/ci/lib/functions.sh
+++ b/dev/ci/lib/functions.sh
@@ -80,8 +80,18 @@ function autodetect_environment()
 	if [ "${GITHUB_ACTIONS:-false}" = "true" ]; then
 		echo "Running in Github Actions: yes"
 		export CACHE_DIR="$RUNNER_TOOL_CACHE/$GITHUB_JOB/$RUNNER_OS"
+	elif [[ "$JENKINS_HOME" != "" ]]; then
+		echo "Running in Jenkins: yes"
+		export IN_JEKINS=true
+		if [ $OS = "linux" ]; then
+		    export CACHE_DIR="$JENKINS_HOME/cache/$JOB_NAME/executor-$EXECUTOR_NUMBER"
+		else
+			require_envvar WORKSPACE "$WORKSPACE"
+			export CACHE_DIR="$WORKSPACE/cache/$JOB_NAME/executor-$EXECUTOR_NUMBER"
+		fi
 	else
-		echo "Running in Github Actions: no"
+		echo "Running in CI: no"
+		export IN_JENKINS=false
 		export CACHE_DIR="$PASSENGER_ROOT/.ci_cache"
 	fi
 	echo "Cache directory: $CACHE_DIR"
@@ -89,20 +99,29 @@ function autodetect_environment()
 
 function sanity_check_environment()
 {
-	if [ "${GITHUB_ACTIONS:-false}" = "true" ]; then
+	if $IN_JENKINS; then
+		if [[ "$JOB_NAME" = "" ]]; then
+			echo "ERROR: Jenkins environment detected, but JOB_NAME environment variable not set." >&2
+			return 1
+		fi
+		if [[ "$EXECUTOR_NUMBER" = "" ]]; then
+			echo "ERROR: Jenkins environment detected, but EXECUTOR_NUMBER environment variable not set." >&2
+			return 1
+		fi
+	elif [ "${GITHUB_ACTIONS:-false}" = "true" ]; then
 		if [ -z "$GITHUB_JOB" ]; then
 			echo "ERROR: Github Actions environment detected, but GITHUB_JOB environment variable not set." >&2
 			return 1
-                else
-                    export "JOB_NAME=$GITHUB_JOB"
+		else
+			export "JOB_NAME=$GITHUB_JOB"
 		fi
 		if [ -z "$GITHUB_RUN_ID" ]; then
 			echo "ERROR: Github Actions environment detected, but GITHUB_RUN_ID environment variable not set." >&2
 			return 1
-                else
-                    export "EXECUTOR_NUMBER=$GITHUB_RUN_ID"
+		else
+			export "EXECUTOR_NUMBER=$GITHUB_RUN_ID"
 		fi
-	fi
+    fi
 }
 
 # The following is necessary to make the C++ tests work.
@@ -112,7 +131,7 @@ function sanity_check_environment()
 function add_bundler_path_to_gem_path()
 {
 	local bundle_path
-
+	
 	if bundle_path=$(bundle show rake); then
 		bundle_path=$(dirname "$bundle_path")
 		bundle_path=$(dirname "$bundle_path")
diff --git a/dev/ci/lib/set-container-envvars.sh b/dev/ci/lib/set-container-envvars.sh
index 50626f25a6..14836c2ab8 100644
--- a/dev/ci/lib/set-container-envvars.sh
+++ b/dev/ci/lib/set-container-envvars.sh
@@ -24,30 +24,40 @@ export CCACHE_LOGFILE="$(pwd)/buildout/testlogs/ccache.log"
 export NOEXEC_DISABLE=1
 
 if [[ "$EXECUTOR_NUMBER" != "" ]]; then
+if [ "${GITHUB_ACTIONS:-false}" = "false" ]; then
+	(( TEST_PORT_BASE=64000+EXECUTOR_NUMBER*10 ))
+else
 	(( TEST_PORT_BASE=64000 ))
+fi
 	export TEST_PORT_BASE
 fi
 
-if [[ "$OS" != macos ]]; then
+if [[ "$OS" = macos ]]; then
+    if [ "${GITHUB_ACTIONS:-false}" = "false" ]; then
+	# Ensure that Homebrew tools can be found
+	eval "$(/usr/libexec/path_helper -s)"
+    fi
+else
 	export LC_CTYPE=C.UTF-8
 fi
 
 if [[ -f ~/.rvm/scripts/rvm ]]; then
-    # shellcheck source=/dev/null
-    source ~/.rvm/scripts/rvm
+	# shellcheck source=/dev/null
+	source ~/.rvm/scripts/rvm
 elif [[ -f /usr/local/rvm/scripts/rvm ]]; then
-    # shellcheck source=/dev/null
-    source /usr/local/rvm/scripts/rvm
+	# shellcheck source=/dev/null
+	source /usr/local/rvm/scripts/rvm
 fi
 
 if command -v rvm; then
-    if [[ "$TEST_RUBY_VERSION" != "" ]]; then
-        header2 "Using Ruby version $TEST_RUBY_VERSION"
-        run rvm use "$TEST_RUBY_VERSION"
-        echo
-    fi
-    # RVM's cd override causes problems (probably thanks to bash
-    # error handling being weird and quirky:
-    # https://news.ycombinator.com/item?id=14321213)
-    unset cd
+if [[ "$TEST_RUBY_VERSION" != "" ]]; then
+	header2 "Using Ruby version $TEST_RUBY_VERSION"
+	run rvm use "$TEST_RUBY_VERSION"
+	echo
+fi
+
+# RVM's cd override causes problems (probably thanks to bash
+# error handling being weird and quirky:
+# https://news.ycombinator.com/item?id=14321213)
+unset cd
 fi
diff --git a/dev/ci/lib/setup-container.sh b/dev/ci/lib/setup-container.sh
index 2b72b7b33a..e0271d0310 100644
--- a/dev/ci/lib/setup-container.sh
+++ b/dev/ci/lib/setup-container.sh
@@ -18,9 +18,16 @@ header2 "Creating test/config.json"
 if [[ "$OS" = linux ]]; then
 	run cp test/config.json.travis test/config.json
 else
+
+    if [ "${GITHUB_ACTIONS:-false}" = "true" ]; then
+        KEYCHAIN_PATH='/Library/Keychains/System.keychain'
+    else
+        KEYCHAIN_PATH='~/Library/Keychains/login.keychain-db'
+    fi
+
     sed \
         -e "s/_AUTHORITY_/Developer/" \
-        -e "s|_KEYCHAIN_|/Library/Keychains/System.keychain|" \
+        -e "s|_KEYCHAIN_|$KEYCHAIN_PATH|" \
         -e "s/_USER_/$USER/" \
         test/config.json.travis-osx > test/config.json
 fi
diff --git a/dev/ci/setup-host b/dev/ci/setup-host
index b1ee944e6f..fbed8658d4 100755
--- a/dev/ci/setup-host
+++ b/dev/ci/setup-host
@@ -19,7 +19,7 @@ if [[ "$OS" = macos && "$1" = "" ]]; then
 	exit 1
 fi
 
-if [ "${GITHUB_ACTIONS:-false}" = "true" ]; then
+if [ "${CI:-false}" = "true" ]; then
 	# Relax permissions. Necessary for unit tests which test permissions.
 	header2 "Relaxing file permissions"
 	echo "+ Setting umask"
@@ -31,9 +31,10 @@ if [ "${GITHUB_ACTIONS:-false}" = "true" ]; then
 	find ./* -type d -print0 | xargs -0 -n 512 chmod g+rx,o+rx
 
 	# Create this file now because otherwise it would be owned by root,
+	# which CI runner cannot remove.
 	run touch test/test.log
 
-        if [ "$OS" = "macos" ]; then
+        if [ "${GITHUB_ACTIONS:-false}" = "true" ] && [ "$OS" = "macos" ]; then
             brew update
             brew install ccache
             sudo security authorizationdb write com.apple.trust-settings.admin allow
diff --git a/dev/ci/tests/homebrew-packaging/setup b/dev/ci/tests/homebrew-packaging/setup
index 8208009507..7dcb2b2c72 100644
--- a/dev/ci/tests/homebrew-packaging/setup
+++ b/dev/ci/tests/homebrew-packaging/setup
@@ -1,13 +1,26 @@
 #!/usr/bin/env bash
 set -e
 
-if ! gem list | grep -qE '^rack '; then
+if command -v rvm-exec; then
+    GEM_COMMAND='rvm-exec system gem'
+    RAKE_COMMAND='rvm-exec system rake'
+    SUDO_COMMAND='rvmsudo'
+else
+    GEM_COMMAND='gem'
+    RAKE_COMMAND='rake'
+    SUDO_COMMAND='sudo'
+fi
+
+# rvm or system ruby
+if ! $GEM_COMMAND list | grep -qE '^rack '; then
 	# The native packaging test runs passenger-install-*-module with the system Ruby,
 	# which in turn requires the 'rack' gem to be installed in the system Ruby's
 	# default RubyGems path. 'rake test:install_deps' installs to a local bundler
 	# directory but not to the default RubyGems path.
-	retry_run 3 sudo gem install rack --no-document
+	export rvmsudo_secure_path=0
+	retry_run 3 $SUDO_COMMAND $GEM_COMMAND install rack --no-document
 fi
-retry_run 3 rake test:install_deps DEVDEPS_DEFAULT=no BASE_DEPS=yes SUDO=yes
+retry_run 3 $RAKE_COMMAND test:install_deps DEVDEPS_DEFAULT=no BASE_DEPS=yes SUDO=yes
+# just system ruby
 retry_run 3 gem install bundler -v '~>1.0' --no-document
 retry_run 3 rake test:install_deps BASE_DEPS=yes

From 57ae130b69626d4eba4265818463dd2d612b28af Mon Sep 17 00:00:00 2001
From: Camden Narzt <c.narzt@me.com>
Date: Mon, 30 Sep 2024 12:08:15 -0600
Subject: [PATCH 08/16] =?UTF-8?q?revert=20a=20change=20that=20didn?=
 =?UTF-8?q?=E2=80=99t=20help=20fix=20jenkins?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 dev/ci/lib/set-container-envvars.sh | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/dev/ci/lib/set-container-envvars.sh b/dev/ci/lib/set-container-envvars.sh
index 14836c2ab8..8b01ae5efe 100644
--- a/dev/ci/lib/set-container-envvars.sh
+++ b/dev/ci/lib/set-container-envvars.sh
@@ -32,12 +32,7 @@ fi
 	export TEST_PORT_BASE
 fi
 
-if [[ "$OS" = macos ]]; then
-    if [ "${GITHUB_ACTIONS:-false}" = "false" ]; then
-	# Ensure that Homebrew tools can be found
-	eval "$(/usr/libexec/path_helper -s)"
-    fi
-else
+if [[ "$OS" != macos ]]; then
 	export LC_CTYPE=C.UTF-8
 fi
 

From 8ee32cc985be64a97b582a6674d5bb1153b1face Mon Sep 17 00:00:00 2001
From: Camden Narzt <c.narzt@me.com>
Date: Mon, 30 Sep 2024 12:09:40 -0600
Subject: [PATCH 09/16] =?UTF-8?q?Revert=20"revert=20a=20change=20that=20di?=
 =?UTF-8?q?dn=E2=80=99t=20help=20fix=20jenkins"?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This reverts commit 57ae130b69626d4eba4265818463dd2d612b28af.
---
 dev/ci/lib/set-container-envvars.sh | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/dev/ci/lib/set-container-envvars.sh b/dev/ci/lib/set-container-envvars.sh
index 8b01ae5efe..14836c2ab8 100644
--- a/dev/ci/lib/set-container-envvars.sh
+++ b/dev/ci/lib/set-container-envvars.sh
@@ -32,7 +32,12 @@ fi
 	export TEST_PORT_BASE
 fi
 
-if [[ "$OS" != macos ]]; then
+if [[ "$OS" = macos ]]; then
+    if [ "${GITHUB_ACTIONS:-false}" = "false" ]; then
+	# Ensure that Homebrew tools can be found
+	eval "$(/usr/libexec/path_helper -s)"
+    fi
+else
 	export LC_CTYPE=C.UTF-8
 fi
 

From 571d542067ba475db617806a3934d467f1ba8d7b Mon Sep 17 00:00:00 2001
From: Camden Narzt <c.narzt@me.com>
Date: Tue, 1 Oct 2024 13:45:41 -0600
Subject: [PATCH 10/16] bump binary automation

---
 CHANGELOG          | 11 ++++++++++-
 packaging/binaries |  2 +-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 3e1ee91260..703c66b085 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,15 @@
 Release 6.0.24 (Not yet released)
 -------------
- *
+ * Updated various library versions used in precompiled binaries (used for e.g. gem installs):
+   - ccache 4.10.1 -> 4.10.2
+   - cmake 3.30.1 -> 3.30.4
+   - curl 8.8.0 -> 8.10.1
+   - git 2.45.2 -> 2.46.2
+   - openssl 3.3.1 -> 3.3.2
+   - rubygems 3.5.16 -> 3.5.20
+   - rubies:
+     - 3.2.4 -> 3.2.5
+     - 3.3.4 -> 3.3.5
 
 
 Release 6.0.23
diff --git a/packaging/binaries b/packaging/binaries
index 9d46190d1b..258988c3eb 160000
--- a/packaging/binaries
+++ b/packaging/binaries
@@ -1 +1 @@
-Subproject commit 9d46190d1b2123ccbe9bb373f87484d7b30a3f9b
+Subproject commit 258988c3eb02a80861a5ed3c606c7959857163db

From 8f7da27496ad73d76c443fc3467f8fead6fff6f7 Mon Sep 17 00:00:00 2001
From: Camden Narzt <c.narzt@me.com>
Date: Tue, 1 Oct 2024 13:50:53 -0600
Subject: [PATCH 11/16] update changelog

---
 CHANGELOG | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG b/CHANGELOG
index 703c66b085..9367dc22dd 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,6 @@
 Release 6.0.24 (Not yet released)
 -------------
+ * [Ruby] Specify rackup version to avoid broken 1.0 gem. Closes GH-2559.
  * Updated various library versions used in precompiled binaries (used for e.g. gem installs):
    - ccache 4.10.1 -> 4.10.2
    - cmake 3.30.1 -> 3.30.4

From b4d42a47c7582b094540b2960bcd0369510b7e12 Mon Sep 17 00:00:00 2001
From: Camden Narzt <c.narzt@me.com>
Date: Wed, 2 Oct 2024 10:42:05 -0600
Subject: [PATCH 12/16] update changelog

---
 CHANGELOG | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG b/CHANGELOG
index 9367dc22dd..8bc5b58327 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,7 @@
 Release 6.0.24 (Not yet released)
 -------------
  * [Ruby] Specify rackup version to avoid broken 1.0 gem. Closes GH-2559.
+ * Upgrades Boost from 1.85 -> 1.86.
  * Updated various library versions used in precompiled binaries (used for e.g. gem installs):
    - ccache 4.10.1 -> 4.10.2
    - cmake 3.30.1 -> 3.30.4

From 17147bcacf7dcf551e03bf07f7c86a9916b2378c Mon Sep 17 00:00:00 2001
From: "Hongli Lai (Phusion)" <hongli@phusion.nl>
Date: Thu, 3 Oct 2024 16:37:45 +0200
Subject: [PATCH 13/16] Improve VSCode IntelliSense support

---
 .vscode/c_cpp_properties.json                 |  5 +-
 .vscode/settings.json                         | 57 ++++++++++++++++++-
 .../Group/InitializationAndShutdown.cpp       |  8 +++
 .../ApplicationPool/Group/InternalUtils.cpp   |  9 +++
 .../Group/LifetimeAndBasics.cpp               |  8 +++
 .../ApplicationPool/Group/Miscellaneous.cpp   |  9 +++
 .../ApplicationPool/Group/OutOfBandWork.cpp   |  9 +++
 .../Group/ProcessListManagement.cpp           | 14 ++++-
 .../Group/SessionManagement.cpp               |  8 +++
 .../Group/SpawningAndRestarting.cpp           |  8 +++
 .../ApplicationPool/Group/StateInspection.cpp |  8 +++
 .../ApplicationPool/Group/Verification.cpp    |  8 +++
 .../Pool/AnalyticsCollection.cpp              |  5 ++
 .../Pool/GarbageCollection.cpp                |  5 ++
 .../ApplicationPool/Pool/GeneralUtils.cpp     |  5 ++
 .../Core/ApplicationPool/Pool/GroupUtils.cpp  |  5 ++
 .../Pool/InitializationAndShutdown.cpp        |  5 ++
 .../ApplicationPool/Pool/Miscellaneous.cpp    |  5 ++
 .../ApplicationPool/Pool/ProcessUtils.cpp     |  5 ++
 .../ApplicationPool/Pool/StateInspection.cpp  |  5 ++
 20 files changed, 182 insertions(+), 9 deletions(-)

diff --git a/.vscode/c_cpp_properties.json b/.vscode/c_cpp_properties.json
index 2e099e109b..5f47167638 100644
--- a/.vscode/c_cpp_properties.json
+++ b/.vscode/c_cpp_properties.json
@@ -7,7 +7,6 @@
                 "${workspaceFolder}/src/agent",
                 "${workspaceFolder}/src/cxx_supportlib",
                 "${workspaceFolder}/src/cxx_supportlib/vendor-copy",
-                "${workspaceFolder}/src/cxx_supportlib/vendor-copy/websocketpp",
                 "${workspaceFolder}/src/cxx_supportlib/vendor-copy/libuv/include",
                 "${workspaceFolder}/src/cxx_supportlib/vendor-modified",
                 "${workspaceFolder}/src/cxx_supportlib/vendor-modified/libev",
@@ -31,10 +30,8 @@
                 "/System/Library/Frameworks",
                 "/Library/Frameworks"
             ],
-            "compilerPath": "/usr/bin/clang",
             "cStandard": "c11",
-            "cppStandard": "c++17",
-            "intelliSenseMode": "clang-x64"
+            "cppStandard": "c++17"
         }
     ],
     "version": 4
diff --git a/.vscode/settings.json b/.vscode/settings.json
index 9fe901b080..33a0b721cb 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -44,8 +44,59 @@
         "string_view": "cpp",
         "unordered_map": "cpp",
         "valarray": "cpp",
-        "vector": "cpp"
+        "vector": "cpp",
+        "__node_handle": "cpp",
+        "__threading_support": "cpp",
+        "__verbose_abort": "cpp",
+        "any": "cpp",
+        "bitset": "cpp",
+        "cctype": "cpp",
+        "charconv": "cpp",
+        "cinttypes": "cpp",
+        "clocale": "cpp",
+        "cmath": "cpp",
+        "codecvt": "cpp",
+        "condition_variable": "cpp",
+        "csignal": "cpp",
+        "cstdarg": "cpp",
+        "cstddef": "cpp",
+        "cstdint": "cpp",
+        "cstdio": "cpp",
+        "cstdlib": "cpp",
+        "cstring": "cpp",
+        "ctime": "cpp",
+        "cwchar": "cpp",
+        "cwctype": "cpp",
+        "execution": "cpp",
+        "forward_list": "cpp",
+        "fstream": "cpp",
+        "future": "cpp",
+        "iomanip": "cpp",
+        "ios": "cpp",
+        "iosfwd": "cpp",
+        "iostream": "cpp",
+        "istream": "cpp",
+        "limits": "cpp",
+        "mutex": "cpp",
+        "new": "cpp",
+        "optional": "cpp",
+        "ostream": "cpp",
+        "print": "cpp",
+        "queue": "cpp",
+        "ratio": "cpp",
+        "shared_mutex": "cpp",
+        "source_location": "cpp",
+        "span": "cpp",
+        "sstream": "cpp",
+        "stack": "cpp",
+        "stdexcept": "cpp",
+        "streambuf": "cpp",
+        "strstream": "cpp",
+        "unordered_set": "cpp",
+        "variant": "cpp",
+        "algorithm": "cpp"
     },
-    "C_Cpp.intelliSenseEngine": "Default",
-    "C_Cpp.intelliSenseEngineFallback": "Enabled"
+    "C_Cpp.intelliSenseEngineFallback": "enabled",
+    "C_Cpp.default.cStandard": "c11",
+    "C_Cpp.default.cppStandard": "c++14"
 }
diff --git a/src/agent/Core/ApplicationPool/Group/InitializationAndShutdown.cpp b/src/agent/Core/ApplicationPool/Group/InitializationAndShutdown.cpp
index 768331746b..17d7ea73a4 100644
--- a/src/agent/Core/ApplicationPool/Group/InitializationAndShutdown.cpp
+++ b/src/agent/Core/ApplicationPool/Group/InitializationAndShutdown.cpp
@@ -23,6 +23,12 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_GROUP_INITIALIZATION_AND_SHUTDOWN_CPP_
+#define _PASSENGER_APPLICATION_POOL_GROUP_INITIALIZATION_AND_SHUTDOWN_CPP_
+
+#ifdef INTELLISENSE
+	#include <Core/ApplicationPool/Pool.h>
+#endif
 #include <Core/ApplicationPool/Group.h>
 
 /*************************************************************************
@@ -179,3 +185,5 @@ Group::shutdown(const Callback &callback,
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_GROUP_INITIALIZATION_AND_SHUTDOWN_CPP_
diff --git a/src/agent/Core/ApplicationPool/Group/InternalUtils.cpp b/src/agent/Core/ApplicationPool/Group/InternalUtils.cpp
index 034e43ce31..c92c416f77 100644
--- a/src/agent/Core/ApplicationPool/Group/InternalUtils.cpp
+++ b/src/agent/Core/ApplicationPool/Group/InternalUtils.cpp
@@ -23,7 +23,14 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_GROUP_INTERNAL_UTILS_CPP_
+#define _PASSENGER_APPLICATION_POOL_GROUP_INTERNAL_UTILS_CPP_
+
+#ifdef INTELLISENSE
+	#include <Core/ApplicationPool/Pool.h>
+#endif
 #include <Core/ApplicationPool/Group.h>
+#include <iterator>
 
 /*************************************************************************
  *
@@ -374,3 +381,5 @@ Group::callAbortLongRunningConnectionsCallback(const ProcessPtr &process) {
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_GROUP_INTERNAL_UTILS_CPP_
diff --git a/src/agent/Core/ApplicationPool/Group/LifetimeAndBasics.cpp b/src/agent/Core/ApplicationPool/Group/LifetimeAndBasics.cpp
index 079162ba6a..cc41fa9cc5 100644
--- a/src/agent/Core/ApplicationPool/Group/LifetimeAndBasics.cpp
+++ b/src/agent/Core/ApplicationPool/Group/LifetimeAndBasics.cpp
@@ -23,6 +23,12 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_GROUP_LIFETIME_AND_BASICS_CPP_
+#define _PASSENGER_APPLICATION_POOL_GROUP_LIFETIME_AND_BASICS_CPP_
+
+#ifdef INTELLISENSE
+	#include <Core/ApplicationPool/Pool.h>
+#endif
 #include <Core/ApplicationPool/Group.h>
 
 /*************************************************************************
@@ -107,3 +113,5 @@ Group::getWrapperRegistry() const {
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_GROUP_LIFETIME_AND_BASICS_CPP_
diff --git a/src/agent/Core/ApplicationPool/Group/Miscellaneous.cpp b/src/agent/Core/ApplicationPool/Group/Miscellaneous.cpp
index 8af3446b51..04e7a7d1f5 100644
--- a/src/agent/Core/ApplicationPool/Group/Miscellaneous.cpp
+++ b/src/agent/Core/ApplicationPool/Group/Miscellaneous.cpp
@@ -23,6 +23,13 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+
+#ifndef _PASSENGER_APPLICATION_POOL_GROUP_MISCELLANEOUS_CPP_
+#define _PASSENGER_APPLICATION_POOL_GROUP_MISCELLANEOUS_CPP_
+
+#ifdef INTELLISENSE
+	#include <Core/ApplicationPool/Pool.h>
+#endif
 #include <Core/ApplicationPool/Group.h>
 
 /*************************************************************************
@@ -65,3 +72,5 @@ Group::authorizeByApiKey(const ApiKey &key) const {
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_GROUP_MISCELLANEOUS_CPP_
diff --git a/src/agent/Core/ApplicationPool/Group/OutOfBandWork.cpp b/src/agent/Core/ApplicationPool/Group/OutOfBandWork.cpp
index eb540b8f21..860c078897 100644
--- a/src/agent/Core/ApplicationPool/Group/OutOfBandWork.cpp
+++ b/src/agent/Core/ApplicationPool/Group/OutOfBandWork.cpp
@@ -23,6 +23,13 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+
+#ifndef _PASSENGER_APPLICATION_POOL_GROUP_OUT_OF_BAND_WORK_CPP_
+#define _PASSENGER_APPLICATION_POOL_GROUP_OUT_OF_BAND_WORK_CPP_
+
+#ifdef INTELLISENSE
+	#include <Core/ApplicationPool/Pool.h>
+#endif
 #include <Core/ApplicationPool/Group.h>
 #include <IOTools/MessageSerialization.h>
 
@@ -322,3 +329,5 @@ Group::requestOOBW(const ProcessPtr &process) {
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_GROUP_OUT_OF_BAND_WORK_CPP_
diff --git a/src/agent/Core/ApplicationPool/Group/ProcessListManagement.cpp b/src/agent/Core/ApplicationPool/Group/ProcessListManagement.cpp
index 94438ff766..f387d13c70 100644
--- a/src/agent/Core/ApplicationPool/Group/ProcessListManagement.cpp
+++ b/src/agent/Core/ApplicationPool/Group/ProcessListManagement.cpp
@@ -23,6 +23,12 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_GROUP_PROCESS_LIST_MANAGEMENT_CPP_
+#define _PASSENGER_APPLICATION_POOL_GROUP_PROCESS_LIST_MANAGEMENT_CPP_
+
+#ifdef INTELLISENSE
+	#include <Core/ApplicationPool/Pool.h>
+#endif
 #include <Core/ApplicationPool/Group.h>
 
 /*************************************************************************
@@ -222,6 +228,7 @@ void
 Group::removeFromDisableWaitlist(const ProcessPtr &p, DisableResult result,
 	boost::container::vector<Callback> &postLockActions)
 {
+	const deque<DisableWaiter> &disableWaitlist = this->disableWaitlist;
 	deque<DisableWaiter>::const_iterator it, end = disableWaitlist.end();
 	deque<DisableWaiter> newList;
 	for (it = disableWaitlist.begin(); it != end; it++) {
@@ -233,7 +240,7 @@ Group::removeFromDisableWaitlist(const ProcessPtr &p, DisableResult result,
 			newList.push_back(waiter);
 		}
 	}
-	disableWaitlist = newList;
+	this->disableWaitlist = newList;
 }
 
 void
@@ -428,6 +435,7 @@ Group::attach(const ProcessPtr &process,
 	/* Now that there are enough resources, relevant processes in
 	 * 'disableWaitlist' can be disabled.
 	 */
+	const deque<DisableWaiter> &disableWaitlist = this->disableWaitlist;
 	deque<DisableWaiter>::const_iterator it, end = disableWaitlist.end();
 	deque<DisableWaiter> newDisableWaitlist;
 	for (it = disableWaitlist.begin(); it != end; it++) {
@@ -451,7 +459,7 @@ Group::attach(const ProcessPtr &process,
 			newDisableWaitlist.push_back(waiter);
 		}
 	}
-	disableWaitlist = newDisableWaitlist;
+	this->disableWaitlist = newDisableWaitlist;
 
 	// Update GC sleep timer.
 	wakeUpGarbageCollector();
@@ -616,3 +624,5 @@ Group::disable(const ProcessPtr &process, const DisableCallback &callback) {
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_GROUP_PROCESS_LIST_MANAGEMENT_CPP_
diff --git a/src/agent/Core/ApplicationPool/Group/SessionManagement.cpp b/src/agent/Core/ApplicationPool/Group/SessionManagement.cpp
index a9e9510077..2ce3fc8689 100644
--- a/src/agent/Core/ApplicationPool/Group/SessionManagement.cpp
+++ b/src/agent/Core/ApplicationPool/Group/SessionManagement.cpp
@@ -23,6 +23,12 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_GROUP_SESSION_MANAGEMENT_CPP_
+#define _PASSENGER_APPLICATION_POOL_GROUP_SESSION_MANAGEMENT_CPP_
+
+#ifdef INTELLISENSE
+	#include <Core/ApplicationPool/Implementation.cpp>
+#endif
 #include <Core/ApplicationPool/Group.h>
 
 /*************************************************************************
@@ -336,3 +342,5 @@ Group::get(const Options &newOptions, const GetCallback &callback,
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_GROUP_SESSION_MANAGEMENT_CPP_
diff --git a/src/agent/Core/ApplicationPool/Group/SpawningAndRestarting.cpp b/src/agent/Core/ApplicationPool/Group/SpawningAndRestarting.cpp
index b2048231b7..3f9b9963df 100644
--- a/src/agent/Core/ApplicationPool/Group/SpawningAndRestarting.cpp
+++ b/src/agent/Core/ApplicationPool/Group/SpawningAndRestarting.cpp
@@ -23,6 +23,12 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_GROUP_SPAWNING_AND_RESTARTING_CPP_
+#define _PASSENGER_APPLICATION_POOL_GROUP_SPAWNING_AND_RESTARTING_CPP_
+
+#ifdef INTELLISENSE
+	#include <Core/ApplicationPool/Implementation.cpp>
+#endif
 #include <Core/ApplicationPool/Group.h>
 
 /*************************************************************************
@@ -485,3 +491,5 @@ Group::allowSpawn() const {
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_GROUP_SPAWNING_AND_RESTARTING_CPP_
diff --git a/src/agent/Core/ApplicationPool/Group/StateInspection.cpp b/src/agent/Core/ApplicationPool/Group/StateInspection.cpp
index 54834e3c5b..55b0ae2c5d 100644
--- a/src/agent/Core/ApplicationPool/Group/StateInspection.cpp
+++ b/src/agent/Core/ApplicationPool/Group/StateInspection.cpp
@@ -23,6 +23,12 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_GROUP_STATE_INSPECTION_CPP_
+#define _PASSENGER_APPLICATION_POOL_GROUP_STATE_INSPECTION_CPP_
+
+#ifdef INTELLISENSE
+	#include <Core/ApplicationPool/Implementation.cpp>
+#endif
 #include <Core/ApplicationPool/Group.h>
 #include <FileTools/PathManip.h>
 #include <cassert>
@@ -303,3 +309,5 @@ Group::inspectConfigInAdminPanelFormat(Json::Value &result) const {
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_GROUP_STATE_INSPECTION_CPP_
diff --git a/src/agent/Core/ApplicationPool/Group/Verification.cpp b/src/agent/Core/ApplicationPool/Group/Verification.cpp
index ad6b59accc..93cb46bf20 100644
--- a/src/agent/Core/ApplicationPool/Group/Verification.cpp
+++ b/src/agent/Core/ApplicationPool/Group/Verification.cpp
@@ -23,6 +23,12 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_GROUP_VERIFICATION_CPP_
+#define _PASSENGER_APPLICATION_POOL_GROUP_VERIFICATION_CPP_
+
+#ifdef INTELLISENSE
+	#include <Core/ApplicationPool/Implementation.cpp>
+#endif
 #include <Core/ApplicationPool/Group.h>
 
 /*************************************************************************
@@ -158,3 +164,5 @@ Group::verifyNoRequestsOnGetWaitlistAreRoutable() const {
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_GROUP_VERIFICATION_CPP_
diff --git a/src/agent/Core/ApplicationPool/Pool/AnalyticsCollection.cpp b/src/agent/Core/ApplicationPool/Pool/AnalyticsCollection.cpp
index 647bb96b5c..6ce93d3f5c 100644
--- a/src/agent/Core/ApplicationPool/Pool/AnalyticsCollection.cpp
+++ b/src/agent/Core/ApplicationPool/Pool/AnalyticsCollection.cpp
@@ -23,6 +23,9 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_POOL_ANALYTICS_COLLECTION_CPP_
+#define _PASSENGER_APPLICATION_POOL_POOL_ANALYTICS_COLLECTION_CPP_
+
 #include <Core/ApplicationPool/Pool.h>
 
 /*************************************************************************
@@ -191,3 +194,5 @@ Pool::realCollectAnalytics() {
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_POOL_ANALYTICS_COLLECTION_CPP_
diff --git a/src/agent/Core/ApplicationPool/Pool/GarbageCollection.cpp b/src/agent/Core/ApplicationPool/Pool/GarbageCollection.cpp
index 708b02bc47..b255e4e001 100644
--- a/src/agent/Core/ApplicationPool/Pool/GarbageCollection.cpp
+++ b/src/agent/Core/ApplicationPool/Pool/GarbageCollection.cpp
@@ -23,6 +23,9 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_POOL_GARBAGE_COLLECTION_CPP_
+#define _PASSENGER_APPLICATION_POOL_POOL_GARBAGE_COLLECTION_CPP_
+
 #include <Core/ApplicationPool/Pool.h>
 
 /*************************************************************************
@@ -199,3 +202,5 @@ Pool::wakeupGarbageCollector() {
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_POOL_GARBAGE_COLLECTION_CPP_
diff --git a/src/agent/Core/ApplicationPool/Pool/GeneralUtils.cpp b/src/agent/Core/ApplicationPool/Pool/GeneralUtils.cpp
index 34167d0e1c..088446908e 100644
--- a/src/agent/Core/ApplicationPool/Pool/GeneralUtils.cpp
+++ b/src/agent/Core/ApplicationPool/Pool/GeneralUtils.cpp
@@ -23,6 +23,9 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_POOL_GENERAL_UTILS_CPP_
+#define _PASSENGER_APPLICATION_POOL_POOL_GENERAL_UTILS_CPP_
+
 #include <Core/ApplicationPool/Pool.h>
 
 /*************************************************************************
@@ -237,3 +240,5 @@ Pool::getRandomGenerator() const {
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_POOL_GENERAL_UTILS_CPP_
diff --git a/src/agent/Core/ApplicationPool/Pool/GroupUtils.cpp b/src/agent/Core/ApplicationPool/Pool/GroupUtils.cpp
index d780d0eb68..46bdf9ef14 100644
--- a/src/agent/Core/ApplicationPool/Pool/GroupUtils.cpp
+++ b/src/agent/Core/ApplicationPool/Pool/GroupUtils.cpp
@@ -23,6 +23,9 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_POOL_GROUP_UTILS_CPP_
+#define _PASSENGER_APPLICATION_POOL_POOL_GROUP_UTILS_CPP_
+
 #include <Core/ApplicationPool/Pool.h>
 
 /*************************************************************************
@@ -288,3 +291,5 @@ Pool::restartGroupsByAppRoot(const StaticString &appRoot, const RestartOptions &
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_POOL_GROUP_UTILS_CPP_
diff --git a/src/agent/Core/ApplicationPool/Pool/InitializationAndShutdown.cpp b/src/agent/Core/ApplicationPool/Pool/InitializationAndShutdown.cpp
index 0f8f1f414a..613b2c1b13 100644
--- a/src/agent/Core/ApplicationPool/Pool/InitializationAndShutdown.cpp
+++ b/src/agent/Core/ApplicationPool/Pool/InitializationAndShutdown.cpp
@@ -23,6 +23,9 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_POOL_INITIALIZATION_AND_SHUTDOWN_CPP_
+#define _PASSENGER_APPLICATION_POOL_POOL_INITIALIZATION_AND_SHUTDOWN_CPP_
+
 #include <Core/ApplicationPool/Pool.h>
 
 /*************************************************************************
@@ -140,3 +143,5 @@ Pool::destroy() {
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_POOL_INITIALIZATION_AND_SHUTDOWN_CPP_
diff --git a/src/agent/Core/ApplicationPool/Pool/Miscellaneous.cpp b/src/agent/Core/ApplicationPool/Pool/Miscellaneous.cpp
index d53ddd278a..7276bd3e49 100644
--- a/src/agent/Core/ApplicationPool/Pool/Miscellaneous.cpp
+++ b/src/agent/Core/ApplicationPool/Pool/Miscellaneous.cpp
@@ -23,6 +23,9 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_POOL_MISCELLANEOUS_CPP_
+#define _PASSENGER_APPLICATION_POOL_POOL_MISCELLANEOUS_CPP_
+
 #include <Core/ApplicationPool/Pool.h>
 
 /*************************************************************************
@@ -250,3 +253,5 @@ Pool::authorizeByUid(uid_t uid, bool lock) const {
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_POOL_MISCELLANEOUS_CPP_
diff --git a/src/agent/Core/ApplicationPool/Pool/ProcessUtils.cpp b/src/agent/Core/ApplicationPool/Pool/ProcessUtils.cpp
index 79c7d4e8ff..0facf16391 100644
--- a/src/agent/Core/ApplicationPool/Pool/ProcessUtils.cpp
+++ b/src/agent/Core/ApplicationPool/Pool/ProcessUtils.cpp
@@ -23,6 +23,9 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_POOL_PROCESS_UTILS_CPP_
+#define _PASSENGER_APPLICATION_POOL_POOL_PROCESS_UTILS_CPP_
+
 #include <Core/ApplicationPool/Pool.h>
 
 /*************************************************************************
@@ -329,3 +332,5 @@ Pool::disableProcess(const StaticString &gupid) {
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_POOL_PROCESS_UTILS_CPP_
diff --git a/src/agent/Core/ApplicationPool/Pool/StateInspection.cpp b/src/agent/Core/ApplicationPool/Pool/StateInspection.cpp
index 27b3fac326..9999ce3adc 100644
--- a/src/agent/Core/ApplicationPool/Pool/StateInspection.cpp
+++ b/src/agent/Core/ApplicationPool/Pool/StateInspection.cpp
@@ -23,6 +23,9 @@
  *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  *  THE SOFTWARE.
  */
+#ifndef _PASSENGER_APPLICATION_POOL_POOL_STATE_INSPECTION_CPP_
+#define _PASSENGER_APPLICATION_POOL_POOL_STATE_INSPECTION_CPP_
+
 #include <Core/ApplicationPool/Pool.h>
 
 /*************************************************************************
@@ -436,3 +439,5 @@ Pool::getGroupCount() const {
 
 } // namespace ApplicationPool2
 } // namespace Passenger
+
+#endif // _PASSENGER_APPLICATION_POOL_POOL_STATE_INSPECTION_CPP_

From b8b395f688fff991c0e0931f34321f8760bd7e13 Mon Sep 17 00:00:00 2001
From: Hongli Lai <hongli@phusion.nl>
Date: Fri, 4 Oct 2024 12:12:23 +0200
Subject: [PATCH 14/16] Improve clangd support

Have clangd define the INTELLISENSE macro so that we can tweak #includes to keep clangd happy.
---
 .clangd | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.clangd b/.clangd
index ef516ada32..b16f5f9c79 100644
--- a/.clangd
+++ b/.clangd
@@ -1,2 +1,2 @@
 CompileFlags:
-  Add: -ferror-limit=0
+  Add: -DINTELLISENSE -ferror-limit=0

From b1102c27c1c9648e86f0d33fb7e32fd573f35f20 Mon Sep 17 00:00:00 2001
From: Hongli Lai <hongli@phusion.nl>
Date: Fri, 4 Oct 2024 12:12:48 +0200
Subject: [PATCH 15/16] Update dependency map, remove unused header

---
 build/support/cxx_dependency_map.rb           | 134 ++++++++++++++++++
 .../ApplicationPool/Group/InternalUtils.cpp   |   1 -
 2 files changed, 134 insertions(+), 1 deletion(-)

diff --git a/build/support/cxx_dependency_map.rb b/build/support/cxx_dependency_map.rb
index 246ea02be3..712865d633 100644
--- a/build/support/cxx_dependency_map.rb
+++ b/build/support/cxx_dependency_map.rb
@@ -750,6 +750,7 @@
    "src/agent/Core/ApplicationPool/Context.h",
    "src/agent/Core/ApplicationPool/Group.h",
    "src/agent/Core/ApplicationPool/Options.h",
+   "src/agent/Core/ApplicationPool/Pool.h",
    "src/agent/Core/ApplicationPool/Process.h",
    "src/agent/Core/ApplicationPool/Session.h",
    "src/agent/Core/ApplicationPool/Socket.h",
@@ -818,6 +819,7 @@
    "src/cxx_supportlib/Utils/FastStringStream.h",
    "src/cxx_supportlib/Utils/IniFile.h",
    "src/cxx_supportlib/Utils/Lock.h",
+   "src/cxx_supportlib/Utils/MessagePassing.h",
    "src/cxx_supportlib/Utils/ScopeGuard.h",
    "src/cxx_supportlib/Utils/SpeedMeter.h",
    "src/cxx_supportlib/Utils/Timer.h",
@@ -848,6 +850,7 @@
    "src/agent/Core/ApplicationPool/Context.h",
    "src/agent/Core/ApplicationPool/Group.h",
    "src/agent/Core/ApplicationPool/Options.h",
+   "src/agent/Core/ApplicationPool/Pool.h",
    "src/agent/Core/ApplicationPool/Process.h",
    "src/agent/Core/ApplicationPool/Session.h",
    "src/agent/Core/ApplicationPool/Socket.h",
@@ -916,6 +919,7 @@
    "src/cxx_supportlib/Utils/FastStringStream.h",
    "src/cxx_supportlib/Utils/IniFile.h",
    "src/cxx_supportlib/Utils/Lock.h",
+   "src/cxx_supportlib/Utils/MessagePassing.h",
    "src/cxx_supportlib/Utils/ScopeGuard.h",
    "src/cxx_supportlib/Utils/SpeedMeter.h",
    "src/cxx_supportlib/Utils/Timer.h",
@@ -946,6 +950,7 @@
    "src/agent/Core/ApplicationPool/Context.h",
    "src/agent/Core/ApplicationPool/Group.h",
    "src/agent/Core/ApplicationPool/Options.h",
+   "src/agent/Core/ApplicationPool/Pool.h",
    "src/agent/Core/ApplicationPool/Process.h",
    "src/agent/Core/ApplicationPool/Session.h",
    "src/agent/Core/ApplicationPool/Socket.h",
@@ -1014,6 +1019,7 @@
    "src/cxx_supportlib/Utils/FastStringStream.h",
    "src/cxx_supportlib/Utils/IniFile.h",
    "src/cxx_supportlib/Utils/Lock.h",
+   "src/cxx_supportlib/Utils/MessagePassing.h",
    "src/cxx_supportlib/Utils/ScopeGuard.h",
    "src/cxx_supportlib/Utils/SpeedMeter.h",
    "src/cxx_supportlib/Utils/Timer.h",
@@ -1044,6 +1050,7 @@
    "src/agent/Core/ApplicationPool/Context.h",
    "src/agent/Core/ApplicationPool/Group.h",
    "src/agent/Core/ApplicationPool/Options.h",
+   "src/agent/Core/ApplicationPool/Pool.h",
    "src/agent/Core/ApplicationPool/Process.h",
    "src/agent/Core/ApplicationPool/Session.h",
    "src/agent/Core/ApplicationPool/Socket.h",
@@ -1112,6 +1119,7 @@
    "src/cxx_supportlib/Utils/FastStringStream.h",
    "src/cxx_supportlib/Utils/IniFile.h",
    "src/cxx_supportlib/Utils/Lock.h",
+   "src/cxx_supportlib/Utils/MessagePassing.h",
    "src/cxx_supportlib/Utils/ScopeGuard.h",
    "src/cxx_supportlib/Utils/SpeedMeter.h",
    "src/cxx_supportlib/Utils/Timer.h",
@@ -1142,6 +1150,7 @@
    "src/agent/Core/ApplicationPool/Context.h",
    "src/agent/Core/ApplicationPool/Group.h",
    "src/agent/Core/ApplicationPool/Options.h",
+   "src/agent/Core/ApplicationPool/Pool.h",
    "src/agent/Core/ApplicationPool/Process.h",
    "src/agent/Core/ApplicationPool/Session.h",
    "src/agent/Core/ApplicationPool/Socket.h",
@@ -1211,6 +1220,7 @@
    "src/cxx_supportlib/Utils/FastStringStream.h",
    "src/cxx_supportlib/Utils/IniFile.h",
    "src/cxx_supportlib/Utils/Lock.h",
+   "src/cxx_supportlib/Utils/MessagePassing.h",
    "src/cxx_supportlib/Utils/ScopeGuard.h",
    "src/cxx_supportlib/Utils/SpeedMeter.h",
    "src/cxx_supportlib/Utils/Timer.h",
@@ -1241,6 +1251,7 @@
    "src/agent/Core/ApplicationPool/Context.h",
    "src/agent/Core/ApplicationPool/Group.h",
    "src/agent/Core/ApplicationPool/Options.h",
+   "src/agent/Core/ApplicationPool/Pool.h",
    "src/agent/Core/ApplicationPool/Process.h",
    "src/agent/Core/ApplicationPool/Session.h",
    "src/agent/Core/ApplicationPool/Socket.h",
@@ -1309,6 +1320,7 @@
    "src/cxx_supportlib/Utils/FastStringStream.h",
    "src/cxx_supportlib/Utils/IniFile.h",
    "src/cxx_supportlib/Utils/Lock.h",
+   "src/cxx_supportlib/Utils/MessagePassing.h",
    "src/cxx_supportlib/Utils/ScopeGuard.h",
    "src/cxx_supportlib/Utils/SpeedMeter.h",
    "src/cxx_supportlib/Utils/Timer.h",
@@ -1338,7 +1350,28 @@
    "src/agent/Core/ApplicationPool/Common.h",
    "src/agent/Core/ApplicationPool/Context.h",
    "src/agent/Core/ApplicationPool/Group.h",
+   "src/agent/Core/ApplicationPool/Group/InitializationAndShutdown.cpp",
+   "src/agent/Core/ApplicationPool/Group/InternalUtils.cpp",
+   "src/agent/Core/ApplicationPool/Group/LifetimeAndBasics.cpp",
+   "src/agent/Core/ApplicationPool/Group/Miscellaneous.cpp",
+   "src/agent/Core/ApplicationPool/Group/OutOfBandWork.cpp",
+   "src/agent/Core/ApplicationPool/Group/ProcessListManagement.cpp",
+   "src/agent/Core/ApplicationPool/Group/SessionManagement.cpp",
+   "src/agent/Core/ApplicationPool/Group/SpawningAndRestarting.cpp",
+   "src/agent/Core/ApplicationPool/Group/StateInspection.cpp",
+   "src/agent/Core/ApplicationPool/Group/Verification.cpp",
+   "src/agent/Core/ApplicationPool/Implementation.cpp",
    "src/agent/Core/ApplicationPool/Options.h",
+   "src/agent/Core/ApplicationPool/Pool.h",
+   "src/agent/Core/ApplicationPool/Pool/AnalyticsCollection.cpp",
+   "src/agent/Core/ApplicationPool/Pool/GarbageCollection.cpp",
+   "src/agent/Core/ApplicationPool/Pool/GeneralUtils.cpp",
+   "src/agent/Core/ApplicationPool/Pool/GroupUtils.cpp",
+   "src/agent/Core/ApplicationPool/Pool/InitializationAndShutdown.cpp",
+   "src/agent/Core/ApplicationPool/Pool/Miscellaneous.cpp",
+   "src/agent/Core/ApplicationPool/Pool/ProcessUtils.cpp",
+   "src/agent/Core/ApplicationPool/Pool/StateInspection.cpp",
+   "src/agent/Core/ApplicationPool/Process.cpp",
    "src/agent/Core/ApplicationPool/Process.h",
    "src/agent/Core/ApplicationPool/Session.h",
    "src/agent/Core/ApplicationPool/Socket.h",
@@ -1347,6 +1380,7 @@
    "src/agent/Core/SpawningKit/Context.h",
    "src/agent/Core/SpawningKit/DirectSpawner.h",
    "src/agent/Core/SpawningKit/DummySpawner.h",
+   "src/agent/Core/SpawningKit/ErrorRenderer.h",
    "src/agent/Core/SpawningKit/Exceptions.h",
    "src/agent/Core/SpawningKit/Factory.h",
    "src/agent/Core/SpawningKit/Handshake/BackgroundIOCapturer.h",
@@ -1372,8 +1406,11 @@
    "src/cxx_supportlib/ConfigKit/Translator.h",
    "src/cxx_supportlib/ConfigKit/Utils.h",
    "src/cxx_supportlib/Constants.h",
+   "src/cxx_supportlib/DataStructures/HashMap.h",
    "src/cxx_supportlib/DataStructures/HashedStaticString.h",
+   "src/cxx_supportlib/DataStructures/LString.h",
    "src/cxx_supportlib/DataStructures/StringKeyTable.h",
+   "src/cxx_supportlib/DataStructures/StringMap.h",
    "src/cxx_supportlib/Exceptions.h",
    "src/cxx_supportlib/FileDescriptor.h",
    "src/cxx_supportlib/FileTools/FileManip.h",
@@ -1382,12 +1419,14 @@
    "src/cxx_supportlib/IOTools/BufferedIO.h",
    "src/cxx_supportlib/IOTools/IOUtils.h",
    "src/cxx_supportlib/IOTools/MessageIO.h",
+   "src/cxx_supportlib/IOTools/MessageSerialization.h",
    "src/cxx_supportlib/JsonTools/JsonUtils.h",
    "src/cxx_supportlib/LoggingKit/Assert.h",
    "src/cxx_supportlib/LoggingKit/Forward.h",
    "src/cxx_supportlib/LoggingKit/Logging.h",
    "src/cxx_supportlib/LoggingKit/LoggingKit.h",
    "src/cxx_supportlib/LveLoggingDecorator.h",
+   "src/cxx_supportlib/MemoryKit/mbuf.h",
    "src/cxx_supportlib/MemoryKit/palloc.h",
    "src/cxx_supportlib/ProcessManagement/Spawn.h",
    "src/cxx_supportlib/ProcessManagement/Utils.h",
@@ -1397,6 +1436,7 @@
    "src/cxx_supportlib/StaticString.h",
    "src/cxx_supportlib/StrIntTools/StrIntUtils.h",
    "src/cxx_supportlib/StrIntTools/StringScanning.h",
+   "src/cxx_supportlib/StrIntTools/Template.h",
    "src/cxx_supportlib/SystemTools/ProcessMetricsCollector.h",
    "src/cxx_supportlib/SystemTools/SystemMetricsCollector.h",
    "src/cxx_supportlib/SystemTools/SystemTime.h",
@@ -1407,6 +1447,7 @@
    "src/cxx_supportlib/Utils/FastStringStream.h",
    "src/cxx_supportlib/Utils/IniFile.h",
    "src/cxx_supportlib/Utils/Lock.h",
+   "src/cxx_supportlib/Utils/MessagePassing.h",
    "src/cxx_supportlib/Utils/ScopeGuard.h",
    "src/cxx_supportlib/Utils/SpeedMeter.h",
    "src/cxx_supportlib/Utils/Timer.h",
@@ -1436,7 +1477,28 @@
    "src/agent/Core/ApplicationPool/Common.h",
    "src/agent/Core/ApplicationPool/Context.h",
    "src/agent/Core/ApplicationPool/Group.h",
+   "src/agent/Core/ApplicationPool/Group/InitializationAndShutdown.cpp",
+   "src/agent/Core/ApplicationPool/Group/InternalUtils.cpp",
+   "src/agent/Core/ApplicationPool/Group/LifetimeAndBasics.cpp",
+   "src/agent/Core/ApplicationPool/Group/Miscellaneous.cpp",
+   "src/agent/Core/ApplicationPool/Group/OutOfBandWork.cpp",
+   "src/agent/Core/ApplicationPool/Group/ProcessListManagement.cpp",
+   "src/agent/Core/ApplicationPool/Group/SessionManagement.cpp",
+   "src/agent/Core/ApplicationPool/Group/SpawningAndRestarting.cpp",
+   "src/agent/Core/ApplicationPool/Group/StateInspection.cpp",
+   "src/agent/Core/ApplicationPool/Group/Verification.cpp",
+   "src/agent/Core/ApplicationPool/Implementation.cpp",
    "src/agent/Core/ApplicationPool/Options.h",
+   "src/agent/Core/ApplicationPool/Pool.h",
+   "src/agent/Core/ApplicationPool/Pool/AnalyticsCollection.cpp",
+   "src/agent/Core/ApplicationPool/Pool/GarbageCollection.cpp",
+   "src/agent/Core/ApplicationPool/Pool/GeneralUtils.cpp",
+   "src/agent/Core/ApplicationPool/Pool/GroupUtils.cpp",
+   "src/agent/Core/ApplicationPool/Pool/InitializationAndShutdown.cpp",
+   "src/agent/Core/ApplicationPool/Pool/Miscellaneous.cpp",
+   "src/agent/Core/ApplicationPool/Pool/ProcessUtils.cpp",
+   "src/agent/Core/ApplicationPool/Pool/StateInspection.cpp",
+   "src/agent/Core/ApplicationPool/Process.cpp",
    "src/agent/Core/ApplicationPool/Process.h",
    "src/agent/Core/ApplicationPool/Session.h",
    "src/agent/Core/ApplicationPool/Socket.h",
@@ -1445,6 +1507,7 @@
    "src/agent/Core/SpawningKit/Context.h",
    "src/agent/Core/SpawningKit/DirectSpawner.h",
    "src/agent/Core/SpawningKit/DummySpawner.h",
+   "src/agent/Core/SpawningKit/ErrorRenderer.h",
    "src/agent/Core/SpawningKit/Exceptions.h",
    "src/agent/Core/SpawningKit/Factory.h",
    "src/agent/Core/SpawningKit/Handshake/BackgroundIOCapturer.h",
@@ -1470,8 +1533,11 @@
    "src/cxx_supportlib/ConfigKit/Translator.h",
    "src/cxx_supportlib/ConfigKit/Utils.h",
    "src/cxx_supportlib/Constants.h",
+   "src/cxx_supportlib/DataStructures/HashMap.h",
    "src/cxx_supportlib/DataStructures/HashedStaticString.h",
+   "src/cxx_supportlib/DataStructures/LString.h",
    "src/cxx_supportlib/DataStructures/StringKeyTable.h",
+   "src/cxx_supportlib/DataStructures/StringMap.h",
    "src/cxx_supportlib/Exceptions.h",
    "src/cxx_supportlib/FileDescriptor.h",
    "src/cxx_supportlib/FileTools/FileManip.h",
@@ -1480,12 +1546,14 @@
    "src/cxx_supportlib/IOTools/BufferedIO.h",
    "src/cxx_supportlib/IOTools/IOUtils.h",
    "src/cxx_supportlib/IOTools/MessageIO.h",
+   "src/cxx_supportlib/IOTools/MessageSerialization.h",
    "src/cxx_supportlib/JsonTools/JsonUtils.h",
    "src/cxx_supportlib/LoggingKit/Assert.h",
    "src/cxx_supportlib/LoggingKit/Forward.h",
    "src/cxx_supportlib/LoggingKit/Logging.h",
    "src/cxx_supportlib/LoggingKit/LoggingKit.h",
    "src/cxx_supportlib/LveLoggingDecorator.h",
+   "src/cxx_supportlib/MemoryKit/mbuf.h",
    "src/cxx_supportlib/MemoryKit/palloc.h",
    "src/cxx_supportlib/ProcessManagement/Spawn.h",
    "src/cxx_supportlib/ProcessManagement/Utils.h",
@@ -1495,6 +1563,7 @@
    "src/cxx_supportlib/StaticString.h",
    "src/cxx_supportlib/StrIntTools/StrIntUtils.h",
    "src/cxx_supportlib/StrIntTools/StringScanning.h",
+   "src/cxx_supportlib/StrIntTools/Template.h",
    "src/cxx_supportlib/SystemTools/ProcessMetricsCollector.h",
    "src/cxx_supportlib/SystemTools/SystemMetricsCollector.h",
    "src/cxx_supportlib/SystemTools/SystemTime.h",
@@ -1505,6 +1574,7 @@
    "src/cxx_supportlib/Utils/FastStringStream.h",
    "src/cxx_supportlib/Utils/IniFile.h",
    "src/cxx_supportlib/Utils/Lock.h",
+   "src/cxx_supportlib/Utils/MessagePassing.h",
    "src/cxx_supportlib/Utils/ScopeGuard.h",
    "src/cxx_supportlib/Utils/SpeedMeter.h",
    "src/cxx_supportlib/Utils/Timer.h",
@@ -1534,7 +1604,28 @@
    "src/agent/Core/ApplicationPool/Common.h",
    "src/agent/Core/ApplicationPool/Context.h",
    "src/agent/Core/ApplicationPool/Group.h",
+   "src/agent/Core/ApplicationPool/Group/InitializationAndShutdown.cpp",
+   "src/agent/Core/ApplicationPool/Group/InternalUtils.cpp",
+   "src/agent/Core/ApplicationPool/Group/LifetimeAndBasics.cpp",
+   "src/agent/Core/ApplicationPool/Group/Miscellaneous.cpp",
+   "src/agent/Core/ApplicationPool/Group/OutOfBandWork.cpp",
+   "src/agent/Core/ApplicationPool/Group/ProcessListManagement.cpp",
+   "src/agent/Core/ApplicationPool/Group/SessionManagement.cpp",
+   "src/agent/Core/ApplicationPool/Group/SpawningAndRestarting.cpp",
+   "src/agent/Core/ApplicationPool/Group/StateInspection.cpp",
+   "src/agent/Core/ApplicationPool/Group/Verification.cpp",
+   "src/agent/Core/ApplicationPool/Implementation.cpp",
    "src/agent/Core/ApplicationPool/Options.h",
+   "src/agent/Core/ApplicationPool/Pool.h",
+   "src/agent/Core/ApplicationPool/Pool/AnalyticsCollection.cpp",
+   "src/agent/Core/ApplicationPool/Pool/GarbageCollection.cpp",
+   "src/agent/Core/ApplicationPool/Pool/GeneralUtils.cpp",
+   "src/agent/Core/ApplicationPool/Pool/GroupUtils.cpp",
+   "src/agent/Core/ApplicationPool/Pool/InitializationAndShutdown.cpp",
+   "src/agent/Core/ApplicationPool/Pool/Miscellaneous.cpp",
+   "src/agent/Core/ApplicationPool/Pool/ProcessUtils.cpp",
+   "src/agent/Core/ApplicationPool/Pool/StateInspection.cpp",
+   "src/agent/Core/ApplicationPool/Process.cpp",
    "src/agent/Core/ApplicationPool/Process.h",
    "src/agent/Core/ApplicationPool/Session.h",
    "src/agent/Core/ApplicationPool/Socket.h",
@@ -1543,6 +1634,7 @@
    "src/agent/Core/SpawningKit/Context.h",
    "src/agent/Core/SpawningKit/DirectSpawner.h",
    "src/agent/Core/SpawningKit/DummySpawner.h",
+   "src/agent/Core/SpawningKit/ErrorRenderer.h",
    "src/agent/Core/SpawningKit/Exceptions.h",
    "src/agent/Core/SpawningKit/Factory.h",
    "src/agent/Core/SpawningKit/Handshake/BackgroundIOCapturer.h",
@@ -1568,8 +1660,11 @@
    "src/cxx_supportlib/ConfigKit/Translator.h",
    "src/cxx_supportlib/ConfigKit/Utils.h",
    "src/cxx_supportlib/Constants.h",
+   "src/cxx_supportlib/DataStructures/HashMap.h",
    "src/cxx_supportlib/DataStructures/HashedStaticString.h",
+   "src/cxx_supportlib/DataStructures/LString.h",
    "src/cxx_supportlib/DataStructures/StringKeyTable.h",
+   "src/cxx_supportlib/DataStructures/StringMap.h",
    "src/cxx_supportlib/Exceptions.h",
    "src/cxx_supportlib/FileDescriptor.h",
    "src/cxx_supportlib/FileTools/FileManip.h",
@@ -1578,12 +1673,14 @@
    "src/cxx_supportlib/IOTools/BufferedIO.h",
    "src/cxx_supportlib/IOTools/IOUtils.h",
    "src/cxx_supportlib/IOTools/MessageIO.h",
+   "src/cxx_supportlib/IOTools/MessageSerialization.h",
    "src/cxx_supportlib/JsonTools/JsonUtils.h",
    "src/cxx_supportlib/LoggingKit/Assert.h",
    "src/cxx_supportlib/LoggingKit/Forward.h",
    "src/cxx_supportlib/LoggingKit/Logging.h",
    "src/cxx_supportlib/LoggingKit/LoggingKit.h",
    "src/cxx_supportlib/LveLoggingDecorator.h",
+   "src/cxx_supportlib/MemoryKit/mbuf.h",
    "src/cxx_supportlib/MemoryKit/palloc.h",
    "src/cxx_supportlib/ProcessManagement/Spawn.h",
    "src/cxx_supportlib/ProcessManagement/Utils.h",
@@ -1593,6 +1690,7 @@
    "src/cxx_supportlib/StaticString.h",
    "src/cxx_supportlib/StrIntTools/StrIntUtils.h",
    "src/cxx_supportlib/StrIntTools/StringScanning.h",
+   "src/cxx_supportlib/StrIntTools/Template.h",
    "src/cxx_supportlib/SystemTools/ProcessMetricsCollector.h",
    "src/cxx_supportlib/SystemTools/SystemMetricsCollector.h",
    "src/cxx_supportlib/SystemTools/SystemTime.h",
@@ -1603,6 +1701,7 @@
    "src/cxx_supportlib/Utils/FastStringStream.h",
    "src/cxx_supportlib/Utils/IniFile.h",
    "src/cxx_supportlib/Utils/Lock.h",
+   "src/cxx_supportlib/Utils/MessagePassing.h",
    "src/cxx_supportlib/Utils/ScopeGuard.h",
    "src/cxx_supportlib/Utils/SpeedMeter.h",
    "src/cxx_supportlib/Utils/Timer.h",
@@ -1632,7 +1731,28 @@
    "src/agent/Core/ApplicationPool/Common.h",
    "src/agent/Core/ApplicationPool/Context.h",
    "src/agent/Core/ApplicationPool/Group.h",
+   "src/agent/Core/ApplicationPool/Group/InitializationAndShutdown.cpp",
+   "src/agent/Core/ApplicationPool/Group/InternalUtils.cpp",
+   "src/agent/Core/ApplicationPool/Group/LifetimeAndBasics.cpp",
+   "src/agent/Core/ApplicationPool/Group/Miscellaneous.cpp",
+   "src/agent/Core/ApplicationPool/Group/OutOfBandWork.cpp",
+   "src/agent/Core/ApplicationPool/Group/ProcessListManagement.cpp",
+   "src/agent/Core/ApplicationPool/Group/SessionManagement.cpp",
+   "src/agent/Core/ApplicationPool/Group/SpawningAndRestarting.cpp",
+   "src/agent/Core/ApplicationPool/Group/StateInspection.cpp",
+   "src/agent/Core/ApplicationPool/Group/Verification.cpp",
+   "src/agent/Core/ApplicationPool/Implementation.cpp",
    "src/agent/Core/ApplicationPool/Options.h",
+   "src/agent/Core/ApplicationPool/Pool.h",
+   "src/agent/Core/ApplicationPool/Pool/AnalyticsCollection.cpp",
+   "src/agent/Core/ApplicationPool/Pool/GarbageCollection.cpp",
+   "src/agent/Core/ApplicationPool/Pool/GeneralUtils.cpp",
+   "src/agent/Core/ApplicationPool/Pool/GroupUtils.cpp",
+   "src/agent/Core/ApplicationPool/Pool/InitializationAndShutdown.cpp",
+   "src/agent/Core/ApplicationPool/Pool/Miscellaneous.cpp",
+   "src/agent/Core/ApplicationPool/Pool/ProcessUtils.cpp",
+   "src/agent/Core/ApplicationPool/Pool/StateInspection.cpp",
+   "src/agent/Core/ApplicationPool/Process.cpp",
    "src/agent/Core/ApplicationPool/Process.h",
    "src/agent/Core/ApplicationPool/Session.h",
    "src/agent/Core/ApplicationPool/Socket.h",
@@ -1641,6 +1761,7 @@
    "src/agent/Core/SpawningKit/Context.h",
    "src/agent/Core/SpawningKit/DirectSpawner.h",
    "src/agent/Core/SpawningKit/DummySpawner.h",
+   "src/agent/Core/SpawningKit/ErrorRenderer.h",
    "src/agent/Core/SpawningKit/Exceptions.h",
    "src/agent/Core/SpawningKit/Factory.h",
    "src/agent/Core/SpawningKit/Handshake/BackgroundIOCapturer.h",
@@ -1666,8 +1787,11 @@
    "src/cxx_supportlib/ConfigKit/Translator.h",
    "src/cxx_supportlib/ConfigKit/Utils.h",
    "src/cxx_supportlib/Constants.h",
+   "src/cxx_supportlib/DataStructures/HashMap.h",
    "src/cxx_supportlib/DataStructures/HashedStaticString.h",
+   "src/cxx_supportlib/DataStructures/LString.h",
    "src/cxx_supportlib/DataStructures/StringKeyTable.h",
+   "src/cxx_supportlib/DataStructures/StringMap.h",
    "src/cxx_supportlib/Exceptions.h",
    "src/cxx_supportlib/FileDescriptor.h",
    "src/cxx_supportlib/FileTools/FileManip.h",
@@ -1676,12 +1800,14 @@
    "src/cxx_supportlib/IOTools/BufferedIO.h",
    "src/cxx_supportlib/IOTools/IOUtils.h",
    "src/cxx_supportlib/IOTools/MessageIO.h",
+   "src/cxx_supportlib/IOTools/MessageSerialization.h",
    "src/cxx_supportlib/JsonTools/JsonUtils.h",
    "src/cxx_supportlib/LoggingKit/Assert.h",
    "src/cxx_supportlib/LoggingKit/Forward.h",
    "src/cxx_supportlib/LoggingKit/Logging.h",
    "src/cxx_supportlib/LoggingKit/LoggingKit.h",
    "src/cxx_supportlib/LveLoggingDecorator.h",
+   "src/cxx_supportlib/MemoryKit/mbuf.h",
    "src/cxx_supportlib/MemoryKit/palloc.h",
    "src/cxx_supportlib/ProcessManagement/Spawn.h",
    "src/cxx_supportlib/ProcessManagement/Utils.h",
@@ -1691,6 +1817,7 @@
    "src/cxx_supportlib/StaticString.h",
    "src/cxx_supportlib/StrIntTools/StrIntUtils.h",
    "src/cxx_supportlib/StrIntTools/StringScanning.h",
+   "src/cxx_supportlib/StrIntTools/Template.h",
    "src/cxx_supportlib/SystemTools/ProcessMetricsCollector.h",
    "src/cxx_supportlib/SystemTools/SystemMetricsCollector.h",
    "src/cxx_supportlib/SystemTools/SystemTime.h",
@@ -1701,6 +1828,7 @@
    "src/cxx_supportlib/Utils/FastStringStream.h",
    "src/cxx_supportlib/Utils/IniFile.h",
    "src/cxx_supportlib/Utils/Lock.h",
+   "src/cxx_supportlib/Utils/MessagePassing.h",
    "src/cxx_supportlib/Utils/ScopeGuard.h",
    "src/cxx_supportlib/Utils/SpeedMeter.h",
    "src/cxx_supportlib/Utils/Timer.h",
@@ -1740,6 +1868,7 @@
    "src/agent/Core/ApplicationPool/Group/SpawningAndRestarting.cpp",
    "src/agent/Core/ApplicationPool/Group/StateInspection.cpp",
    "src/agent/Core/ApplicationPool/Group/Verification.cpp",
+   "src/agent/Core/ApplicationPool/Implementation.cpp",
    "src/agent/Core/ApplicationPool/Options.h",
    "src/agent/Core/ApplicationPool/Pool.h",
    "src/agent/Core/ApplicationPool/Pool/AnalyticsCollection.cpp",
@@ -1787,6 +1916,7 @@
    "src/cxx_supportlib/Constants.h",
    "src/cxx_supportlib/DataStructures/HashMap.h",
    "src/cxx_supportlib/DataStructures/HashedStaticString.h",
+   "src/cxx_supportlib/DataStructures/LString.h",
    "src/cxx_supportlib/DataStructures/StringKeyTable.h",
    "src/cxx_supportlib/DataStructures/StringMap.h",
    "src/cxx_supportlib/Exceptions.h",
@@ -1804,6 +1934,7 @@
    "src/cxx_supportlib/LoggingKit/Logging.h",
    "src/cxx_supportlib/LoggingKit/LoggingKit.h",
    "src/cxx_supportlib/LveLoggingDecorator.h",
+   "src/cxx_supportlib/MemoryKit/mbuf.h",
    "src/cxx_supportlib/MemoryKit/palloc.h",
    "src/cxx_supportlib/ProcessManagement/Spawn.h",
    "src/cxx_supportlib/ProcessManagement/Utils.h",
@@ -6275,6 +6406,7 @@
    "src/cxx_supportlib/Constants.h",
    "src/cxx_supportlib/DataStructures/HashMap.h",
    "src/cxx_supportlib/DataStructures/HashedStaticString.h",
+   "src/cxx_supportlib/DataStructures/LString.h",
    "src/cxx_supportlib/DataStructures/StringKeyTable.h",
    "src/cxx_supportlib/DataStructures/StringMap.h",
    "src/cxx_supportlib/Exceptions.h",
@@ -6287,6 +6419,8 @@
    "src/cxx_supportlib/LoggingKit/Forward.h",
    "src/cxx_supportlib/LoggingKit/Logging.h",
    "src/cxx_supportlib/LoggingKit/LoggingKit.h",
+   "src/cxx_supportlib/MemoryKit/mbuf.h",
+   "src/cxx_supportlib/MemoryKit/palloc.h",
    "src/cxx_supportlib/ProcessManagement/Spawn.h",
    "src/cxx_supportlib/RandomGenerator.h",
    "src/cxx_supportlib/ResourceLocator.h",
diff --git a/src/agent/Core/ApplicationPool/Group/InternalUtils.cpp b/src/agent/Core/ApplicationPool/Group/InternalUtils.cpp
index c92c416f77..75e9b8b040 100644
--- a/src/agent/Core/ApplicationPool/Group/InternalUtils.cpp
+++ b/src/agent/Core/ApplicationPool/Group/InternalUtils.cpp
@@ -30,7 +30,6 @@
 	#include <Core/ApplicationPool/Pool.h>
 #endif
 #include <Core/ApplicationPool/Group.h>
-#include <iterator>
 
 /*************************************************************************
  *

From feec71422e3bf1ae50a2f516469e7a601252ec71 Mon Sep 17 00:00:00 2001
From: "Hongli Lai (Phusion)" <hongli@phusion.nl>
Date: Wed, 2 Oct 2024 17:33:55 +0200
Subject: [PATCH 16/16] Improve precompiled header compatibility with (s)ccache

---
 .gitignore                                    |  1 +
 build/cxx_tests.rb                            | 19 ++++++++++++++-----
 build/test_basics.rb                          |  2 +-
 .../platform_info/compiler.rb                 |  8 ++++++++
 4 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/.gitignore b/.gitignore
index e7862d5614..8da7fe585c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,6 +8,7 @@ autom4te.cache
 *.pyc
 *.dSYM
 *.gch
+*.pch
 *.swp
 *~.nib
 *.pbxuser
diff --git a/build/cxx_tests.rb b/build/cxx_tests.rb
index e3a81be0b2..818b18adea 100644
--- a/build/cxx_tests.rb
+++ b/build/cxx_tests.rb
@@ -158,7 +158,15 @@
 end
 
 let(:test_cxx_flags) do
-  ['-include test/cxx/TestSupport.h'] + basic_test_cxx_flags
+  # Some flags are necessary to make precompiled headers play well with ccache (and possibly also sccache):
+  # https://ccache.dev/manual/4.8.2.html#_precompiled_headers
+  if PlatformInfo.cxx_is_gcc?
+    ['-include test/cxx/TestSupport.h', '-fpch-preprocess']
+  elsif PlatformInfo.cxx_is_clang?
+    ["-include-pch test/cxx/TestSupport.h.#{PlatformInfo.precompiled_header_extension}", '-Xclang', '-fno-pch-timestamp']
+  else
+    ['-include test/cxx/TestSupport.h']
+  end + basic_test_cxx_flags
 end
 
 let(:test_cxx_ldflags) do
@@ -182,7 +190,7 @@
     lambda { {
       :include_paths => test_cxx_include_paths,
       :flags => test_cxx_flags,
-      :deps => 'test/cxx/TestSupport.h.gch'
+      :deps => "test/cxx/TestSupport.h.#{PlatformInfo.precompiled_header_extension}"
     } }
   )
 end
@@ -280,14 +288,15 @@
   end
 end
 
-file('test/cxx/TestSupport.h.gch' => generate_compilation_task_dependencies('test/cxx/TestSupport.h')) do
+file("test/cxx/TestSupport.h.#{PlatformInfo.precompiled_header_extension}" => generate_compilation_task_dependencies('test/cxx/TestSupport.h')) do
   compile_cxx(
-    'test/cxx/TestSupport.h.gch',
+    "test/cxx/TestSupport.h.#{PlatformInfo.precompiled_header_extension}",
     'test/cxx/TestSupport.h',
     :include_paths => test_cxx_include_paths,
     :flags => [
       "-x c++-header",
+      PlatformInfo.cxx_is_clang? ? "-Xclang -emit-pch" : nil,
       basic_test_cxx_flags
-    ].flatten
+    ].compact.flatten
   )
 end
diff --git a/build/test_basics.rb b/build/test_basics.rb
index 5b18793919..90ddaba7e0 100644
--- a/build/test_basics.rb
+++ b/build/test_basics.rb
@@ -34,7 +34,7 @@
 desc "Clean all compiled test files"
 task 'test:clean' do
   sh("rm -rf #{TEST_OUTPUT_DIR}")
-  sh("rm -f test/cxx/*.gch")
+  sh("rm -f test/cxx/*.#{PlatformInfo.precompiled_header_extension} test/cxx/*.gch test/cxx/*.pch")
 end
 
 task :clean => 'test:clean'
diff --git a/src/ruby_supportlib/phusion_passenger/platform_info/compiler.rb b/src/ruby_supportlib/phusion_passenger/platform_info/compiler.rb
index e1e8fcf8d5..de8b4cd858 100644
--- a/src/ruby_supportlib/phusion_passenger/platform_info/compiler.rb
+++ b/src/ruby_supportlib/phusion_passenger/platform_info/compiler.rb
@@ -603,6 +603,14 @@ def self.export_dynamic_flags
       end
     end
 
+    def self.precompiled_header_extension
+      if cxx_is_gcc?
+        'gch'
+      else
+        'pch'
+      end
+    end
+
 
     def self.make
       return string_env('MAKE', find_command('make'))