fix vecvec::bucket::reference and add iterator types

.clang-format

@@ -13,14 +13,14 @@ AlwaysBreakTemplateDeclarations: true
 SpacesBeforeTrailingComments: 2
 IncludeBlocks: Preserve
 IncludeCategories:
-  - Regex:           '^<.*\.h>'
-    Priority:        1
-  - Regex:           '^<c.*'
-    Priority:        2
-  - Regex:           '^<.*'
-    Priority:        4
-  - Regex:           '.*'
-    Priority:        5
+  - Regex: '^<.*\.h>'
+    Priority: 1
+  - Regex: '^<c.*'
+    Priority: 2
+  - Regex: '^<.*'
+    Priority: 4
+  - Regex: '.*'
+    Priority: 5
 ---
 BasedOnStyle: Google
 ColumnLimit: 80
@@ -37,12 +37,11 @@ AlwaysBreakTemplateDeclarations: true
 SpacesBeforeTrailingComments: 2
 IncludeBlocks: Preserve
 IncludeCategories:
-  - Regex:           '^<.*\.h>'
-    Priority:        1
-  - Regex:           '^<c.*'
-    Priority:        2
-    Priority:        3
-  - Regex:           '^<.*'
-    Priority:        4
-  - Regex:           '.*'
-    Priority:        5
+  - Regex: '^<.*\.h>'
+    Priority: 1
+  - Regex: '^<c.*'
+    Priority: 3
+  - Regex: '^<.*'
+    Priority: 4
+  - Regex: '.*'
+    Priority: 5

include/cista/containers/vecvec.h

@@ -21,7 +21,7 @@ struct basic_vecvec {
     using iterator_category = std::random_access_iterator_tag;
     using difference_type = std::ptrdiff_t;
     using pointer = std::add_pointer_t<value_type>;
-    using reference = std::add_lvalue_reference<value_type>;
+    using reference = bucket;
 
     bucket(basic_vecvec* map, index_value_type const i)
         : map_{map}, i_{to_idx(i)} {}
@@ -262,6 +262,8 @@ struct basic_vecvec {
   };
 
   using value_type = bucket;
+  using iterator = bucket;
+  using const_iterator = const_bucket;
 
   bucket operator[](Key const i) { return {this, to_idx(i)}; }
   const_bucket operator[](Key const i) const { return {this, to_idx(i)}; }