diff --git a/execution.bs b/execution.bs
index 0b15fb3..2c77308 100644
--- a/execution.bs
+++ b/execution.bs
@@ -6169,7 +6169,7 @@ namespace std::execution {
namespace std::execution {
template<class Sch>
concept scheduler =
- derived_from<typename Sch::scheduler_concept, scheduler_t> &&
+ derived_from<typename remove_cvref_t<Sch>::scheduler_concept, scheduler_t> &&
queryable<Sch> &&
requires(Sch&& sch) {
{ schedule(std::forward<Sch>(sch)) } -> sender;
@@ -6227,7 +6227,7 @@ namespace std::execution {
namespace std::execution {
template<class Rcvr>
concept receiver =
- derived_from<typename Rcvr::receiver_concept, receiver_t> &&
+ derived_from<typename remove_cvref_t<Rcvr>::receiver_concept, receiver_t> &&
requires(const remove_cvref_t<Rcvr>& rcvr) {
{ get_env(rcvr) } -> queryable;
} &&
@@ -6561,7 +6561,8 @@ namespace std::execution {
1. `product-type` is presented here in
pseudo-code form for the sake of exposition. It can be approximated in
standard C++ with a `tuple`-like implementation that takes care
- to keep the type structural.
+ to keep the type an aggregate that can be used as the initializer of a
+ structured binding declaration.
2. An expression of type
`product-type` is usable as the initializer of a
@@ -7459,7 +7460,7 @@ namespace std::execution {
2. The names `just`, `just_error`, and `just_stopped` denote customization
point objects. Let `just-cpo` be one of `just`,
`just_error`, or `just_stopped`. For a pack of subexpressions `ts`, let `Ts`
- be the template parameter pack `decltype((ts))`. The expression
+ be the pack of types `decltype((ts))`. The expression
just-cpo(ts...) is ill-formed if:
- (movable-value<Ts> &&...) is `false`, or
@@ -8382,7 +8383,7 @@ request but has no recommendataions at present.
given an instance `env`, the expression `get_stop_token(env)` is well-formed
and has type `inplace_stop_token`.
-3. The names `split` and `ensure_started` denote pipeable sender adaptor closure objects.
+3. The names `split` and `ensure_started` denote pipeable sender adaptor objects.
Let the expression `shared-cpo` be one of `split` or
`ensure_started`. For a subexpression `sndr`, let `Sndr` be
`decltype((sndr))`. If sender_in<Sndr, shared-env> is
@@ -8686,7 +8687,7 @@ request but has no recommendataions at present.
2. The member
impls-for<shared-impl-tag>::start
- is initialized with a callable object that has a call operator
+ is initialized with a callable object that has a function call operator
equivalent to the following:
@@ -8704,7 +8705,7 @@ request but has no recommendataions at present.
state.on_stop.emplace(
get_stop_token(get_env(rcvr)),
- on-stop-request{state.sh_state->stop_src})
+ on-stop-request{state.sh_state->stop_src});
2. If `shared-impl-tag` is `ensure-started-impl-tag`,
@@ -8713,15 +8714,15 @@ request but has no recommendataions at present.
3. Otherwise, atomically does the following:
- - Inserts `&state` into `state.sh_state->waiting_states`, and
+ - Inserts `addressof(state)` into `state.sh_state->waiting_states`, and
- Reads the value of `state.sh_state->completed`.
4. If the value read from `state.sh_state->completed` is `true`,
calls state.notify() and returns.
- 4. Otherwise, if `shared-impl-tag` is
- `split-impl-tag`, and if `&state` is the first item added
+ 5. Otherwise, if `shared-impl-tag` is
+ `split-impl-tag`, and if `addressof(state)` is the first item added
to `state.sh_state->waiting_states`, calls
state.sh_state->start-op().
@@ -8751,9 +8752,8 @@ request but has no recommendataions at present.
2. The names `when_all` and `when_all_with_variant` denote customization point
objects. Let `sndrs` be a pack of subexpressions, let `Sndrs` be a pack of
the types `decltype((sndrs))...`, and let `CD` be the type
- common_type_t<DOMAIN-OF(sndrs)...>, where
- DOMAIN-OF(sndr) is the type of
- get-domain-early(sndr). The expressions `when_all(sndrs...)` and
+ common_type_t<decltype(get-domain-early(sndrs))...>.
+ The expressions `when_all(sndrs...)` and
`when_all_with_variant(sndrs...)` are ill-formed if
any of the following is true:
@@ -8768,7 +8768,7 @@ request but has no recommendataions at present.
transform_sender(
CD(),
- make-sender(when_all, {}, sndrs...));
+ make-sender(when_all, {}, sndrs...))
4. The exposition-only class template `impls-for`
@@ -8823,9 +8823,9 @@ request but has no recommendataions at present.
where `e` is the expression:
-
+
- std::forward<Sndr>(sndr).apply(make-state<Rcvr>{get_env(rcvr)})
+ std::forward<Sndr>(sndr).apply(make-state<Rcvr>())
and where `make-state` is the following exposition-only class template:
@@ -8839,8 +8839,6 @@ request but has no recommendataions at present.
template<class Rcvr>
struct make-state {
- const env_of_t<Rcvr>& env;
-
template<max-1-sender-in<env_of_t<Rcvr>>... Sndrs>
auto operator()(auto, auto, Sndrs&&... sndrs) const {
using values_tuple = see below;
@@ -9025,7 +9023,7 @@ request but has no recommendataions at present.
1. `into_variant` adapts a sender with multiple value completion signatures into
a sender with just one value completion signature consisting of a `variant` of `tuple`s.
-2. The name `into_variant` denotes a pipeable sender adaptor closure object. For a
+2. The name `into_variant` denotes a pipeable sender adaptor object. For a
subexpression `sndr`, let `Sndr` be `decltype((sndr))`. If `Sndr` does not
satisfy `sender`, `into_variant(sndr)` is ill-formed.
@@ -9087,7 +9085,7 @@ request but has no recommendataions at present.
sender that never completes with stopped, reporting cancellation by
completing with an disengaged `optional`.
-2. The name `stopped_as_optional` denotes a pipeable sender adaptor closure
+2. The name `stopped_as_optional` denotes a pipeable sender adaptor
object. For a subexpression `sndr`, let `Sndr` be `decltype((sndr))`. The
expression `stopped_as_optional(sndr)` is expression-equivalent to:
@@ -9124,7 +9122,7 @@ request but has no recommendataions at present.
that never completes with stopped, reporting cancellation by completing with
an error.
-2. The name `stopped_as_error` denotes a pipeable sender adaptor closure object.
+2. The name `stopped_as_error` denotes a pipeable sender adaptor object.
For some subexpressions `sndr` and `err`, let `Sndr` be `decltype((sndr))`
and let `Err` be `decltype((err))`. If the type `Sndr` does not satisfy
`sender` or if the type `Err` doesn't satisfy `movable-value`,
@@ -9498,7 +9496,7 @@ request but has no recommendataions at present.
only if it is a function type with one of the following forms:
* set_value_t(Vs...), where `Vs`
- is an parameter pack of object or reference types.
+ is a pack of object or reference types.
* set_error_t(Err), where `Err` is
an object or reference type.
* `set_stopped_t()`
@@ -9511,11 +9509,11 @@ request but has no recommendataions at present.
using gather-signatures = see below;
- 2. Let `Fns...` be a template parameter pack of the arguments of the
+ 2. Let `Fns` be a pack of the arguments of the
`completion_signatures` specialization named by `Completions`, let
- `TagFns` be a template parameter pack of the function
+ `TagFns` be a pack of the function
types in `Fns` whose return types are `Tag`, and let
- Tsn be a template parameter pack
+ Tsn be a pack
of the function argument types in the `n`-th type in
`TagFns`. Then, given two variadic templates
`Tuple` and `Variant`, the type
@@ -9525,7 +9523,7 @@ request but has no recommendataions at present.
Ts0...), META-APPLY(Tuple,
Ts1...), ... META-APPLY(Tuple,
Tsm-1...)), where `m`
- is the size of the parameter pack `TagFns` and
+ is the size of the pack `TagFns` and
META-APPLY(T, As...) is equivalent to:
@@ -9567,8 +9565,6 @@ request but has no recommendataions at present.
-
-
### `execution::transform_completion_signatures` [exec.utils.tfxcmplsigs] ### {#spec-execution.snd_rec_utils.transform_completion_sigs}
1. `transform_completion_signatures` is an alias template used to transform one
@@ -9596,7 +9592,7 @@ request but has no recommendataions at present.
-- end example]
-3. This subclause makes use of the following exposition-only entities:
+3. [exec.utils.tfxcmplsigs] makes use of the following exposition-only entities:
template<class... As>
@@ -9622,8 +9618,8 @@ request but has no recommendataions at present.
}
- 1. `SetValue` shall name an alias template such that for any template
- parameter pack `As...`, the type `SetValue` is either ill-formed
+ 1. `SetValue` shall name an alias template such that for any
+ pack of types `As`, the type `SetValue` is either ill-formed
or else
valid-completion-signatures<SetValue<As...>>
is satisfied.
@@ -9642,7 +9638,7 @@ request but has no recommendataions at present.
named by gather-signatures<set_error_t, InputSignatures,
type_identity_t, error-list>, where
`error-list` is an alias template such that
- error-list<Ts...> names
+ error-list<Ts...> is
type-list<SetError<Ts>...>.
5. Let `Ss` name the type `completion_signatures<>` if
@@ -9654,38 +9650,36 @@ request but has no recommendataions at present.
6. If any of the above types are ill-formed, then
`transform_completion_signatures` is ill-formed,
+ SetValue, SetError, SetStopped>` is ill-formed.
7. Otherwise, `transform_completion_signatures` names the type
+ AdditionalSignatures, SetValue, SetError, SetStopped>` is the type
`completion_signatures` where `Sigs...` is the unique set of
types in all the template arguments of all the `completion_signatures`
- specializations in `[AdditionalSignatures, Vs..., Es..., Ss]`.
+ specializations in the set `AdditionalSignatures, Vs..., Es..., Ss`.
## Execution contexts [exec.ctx] ## {#spec-execution.contexts}
-1. This subclause specifies some execution resources on which work can be
- scheduled.
-
### `run_loop` [exec.run.loop] ### {#spec-execution.contexts.run_loop}
1. A `run_loop` is an execution resource on which work can be scheduled. It
- maintains a simple, thread-safe first-in-first-out queue of work. Its `run()`
+ maintains a thread-safe first-in-first-out queue of work. Its `run()`
member function removes elements from the queue and executes them in a loop
- on whatever thread of execution calls `run()`.
+ on the thread of execution calls `run()`.
2. A `run_loop` instance has an associated count that corresponds to the
- number of work items that are in its queue. Additionally, a `run_loop` has an
+ number of work items that are in its queue. Additionally, a `run_loop` instance has an
associated state that can be one of starting, running,
or finishing.
-3. Concurrent invocations of the member functions of `run_loop`, other than
- `run` and its destructor, do not introduce data races. The member functions
+3. Concurrent invocations of the member functions of `run_loop` other than
+ `run` and its destructor do not introduce data races. The member functions
`pop_front`, `push_back`, and `finish` execute atomically.
-4. Implementations are encouraged to use an intrusive
+4. *Recommended practice:* Implementations are encouraged to use an intrusive
queue of operation states to hold the work units to make scheduling
- allocation-free.
+ allocation-free.
+
namespace std::execution {
@@ -9694,16 +9688,18 @@ request but has no recommendataions at present.
class run-loop-scheduler; // exposition only
class run-loop-sender; // exposition only
struct run-loop-opstate-base { // exposition only
- virtual void execute() = 0;
- run_loop* loop;
- run-loop-opstate-base* next;
+ virtual void execute() = 0; // exposition only
+ run_loop* loop; // exposition only
+ run-loop-opstate-base* next; // exposition only
};
template<receiver_of<completion_signatures<set_value_t()>> Rcvr>
using run-loop-opstate = unspecified; // exposition only
+
+TODO: kebab these:
// [exec.run.loop.members] Member functions:
- run-loop-opstate-base* pop_front(); // exposition only
- void push_back(run-loop-opstate-base*); // exposition only
+ run-loop-opstate-base* pop-front(); // exposition only
+ void push-back(run-loop-opstate-base*); // exposition only
public:
// [exec.run.loop.ctor] construct/copy/destroy
@@ -9726,7 +9722,7 @@ class run-loop-scheduler;
1. `run-loop-scheduler` is an unspecified type that models
- the `scheduler` concept.
+ `scheduler`.
2. Instances of `run-loop-scheduler` remain valid until the
end of the lifetime of the `run_loop` instance from which they were
@@ -9737,17 +9733,21 @@ class run-loop-scheduler;
4. Let `sch` be an expression of type
`run-loop-scheduler`. The expression
- schedule(sch) is not potentially-throwing and has type
- `run-loop-sender`.
+ schedule(sch) has type
+ `run-loop-sender` and is not potentially-throwing
+ if `sch` is not potentially-throwing.
class run-loop-sender;
-1. `run-loop-sender` is an unspecified type such that
- sender-of<run-loop-sender> is `true`.
- Additionally, the types reported by its `error_types` associated type is
- `exception_ptr`, and the value of its `sends_stopped` trait is `true`.
+1. `run-loop-sender` is an unspecified type such that for any
+ type `Env`, completion_signatures_of_t<run-loop-sender, Env>
+ is:
+
+
+ completion_signatures<set_value_t(), set_error_t(exception_ptr), set_stopped_t()>
+
2. An instance of `run-loop-sender` remains valid until the
end of the lifetime of its associated `run_loop` instance.
@@ -9776,7 +9776,7 @@ template<receiver_of<completion_signatures<set_value_t()>> Rcvr>
struct run-loop-opstate;
-1. run-loop-opstate<Rcvr> inherits unambiguously
+1. run-loop-opstate<Rcvr> inherits privately and unambiguously
from `run-loop-opstate-base`.
2. Let `o` be a non-`const` lvalue of type
@@ -9791,8 +9791,8 @@ template<receiver_of<completion_signatures<set_value_t()>> Rcvr>
refers.
* The type run-loop-opstate<Rcvr> overrides
- run-loop-opstate-base::execute() such that
- o.execute() is equivalent to the following:
+ run-loop-opstate-base::execute() such that
+ o.execute() is equivalent to the following:
if (get_stop_token(REC(o)).stop_requested()) {
@@ -9807,7 +9807,7 @@ template<receiver_of<completion_signatures<set_value_t()>> Rcvr>
try {
- o.loop->push_back(&o);
+ o.loop->push-back(&o);
} catch(...) {
set_error(std::move(REC(o)), current_exception());
}
@@ -9832,27 +9832,27 @@ run_loop() noexcept;
#### Member functions [exec.run.loop.members] #### {#spec-execution.contexts.run_loop.members}
-run-loop-opstate-base* pop_front();
+run-loop-opstate-base* pop-front();
1. Effects: Blocks ([defns.block]) until one of the following conditions
is `true`:
* count is `0` and state is finishing, in which case
- `pop_front` returns `nullptr`; or
+ `pop-front` returns `nullptr`; or
* count is greater than `0`, in which case an item is removed from
the front of the queue, count is decremented by `1`, and the
removed item is returned.
-void push_back(run-loop-opstate-base* item);
+void push-back(run-loop-opstate-base* item);
1. Effects: Adds `item` to the back of the queue and increments
count by `1`.
-2. Synchronization: This operation synchronizes with the `pop_front`
+2. Synchronization: This operation synchronizes with the `pop-front`
operation that obtains `item`.
@@ -9869,8 +9869,8 @@ void run();
1. Effects: Equivalent to:
- while (auto* op = pop_front()) {
- op->execute();
+ while (auto* op = pop-front()) {
+ op->execute();
}
@@ -9887,7 +9887,7 @@ void finish();
1. Effects: Changes state to finishing.
-2. Synchronization: This operation synchronizes with all `pop_front`
+2. Synchronization: This operation synchronizes with all `pop-front`
operations on this object.
## Coroutine utilities [exec.coro.utils] ## {#spec-execution.coro_utils}
@@ -9952,7 +9952,7 @@ void finish();
Let `rcvr` be an rvalue expression of type
`awaitable-receiver`, let `crcvr` be a `const`
- lvalue that refers to `rcvr`, let `vs` be a parameter pack of types
+ lvalue that refers to `rcvr`, let `vs` be a pack of types
`Vs...`, and let `err` be an arbitrary expression of type `Err`.
Then: