review comments

Author: Hui Xie

libcxx/include/__flat_map/flat_map.h

@@ -1190,7 +1190,7 @@ template <ranges::input_range _Range,
           class _Allocator = allocator<byte>,
           class            = __enable_if_t<!__is_allocator<_Compare>::value && __is_allocator<_Allocator>::value>>
 flat_map(from_range_t, _Range&&, _Compare = _Compare(), _Allocator = _Allocator())
-    ->flat_map<
+    -> flat_map<
         __range_key_type<_Range>,
         __range_mapped_type<_Range>,
         _Compare,
@@ -1199,7 +1199,7 @@ flat_map(from_range_t, _Range&&, _Compare = _Compare(), _Allocator = _Allocator(
 
 template <ranges::input_range _Range, class _Allocator, class = __enable_if_t<__is_allocator<_Allocator>::value>>
 flat_map(from_range_t, _Range&&, _Allocator)
-    ->flat_map<
+    -> flat_map<
         __range_key_type<_Range>,
         __range_mapped_type<_Range>,
         less<__range_key_type<_Range>>,

libcxx/include/__flat_map/key_value_iterator.h

@@ -32,6 +32,12 @@ _LIBCPP_PUSH_MACROS
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
+/**
+ * __key_value_iterator is a proxy iterator which zips the underlying
+ * _KeyContainer::iterator and the underlying _MappedContainer::iterator.
+ * The two underlying iterators will be incremented/decremented together.
+ * And the reference is a pair of the const key reference and the value reference.
+ */
 template <class _Owner, class _KeyContainer, class _MappedContainer, bool _Const>
 struct __key_value_iterator {
 private:
@@ -54,7 +60,7 @@ struct __key_value_iterator {
 
 public:
   using iterator_concept = random_access_iterator_tag;
-  // `flat_map::iterator` only satisfy "Cpp17InputIterator" named requirements, because
+  // `__key_value_iterator` only satisfy "Cpp17InputIterator" named requirements, because
   // its `reference` is not a reference type.
   // However, to avoid surprising runtime behaviour when it is used with the
   // Cpp17 algorithms or operations, iterator_category is set to random_access_iterator_tag.

libcxx/include/flat_map

@@ -40,7 +40,6 @@ namespace std {
 #include <__assert> // all public C++ headers provide the assertion handler
 #include <__config>
 #include <__flat_map/flat_map.h>
-#include <__flat_map/key_value_iterator.h>
 #include <__flat_map/sorted_unique.h>
 #include <version>