libstdc++: Minor fixes to doxygen comments

libstdc++-v3/ChangeLog:

	* include/bits/uses_allocator.h: Add missing @file comment.
	* include/bits/regex.tcc: Remove stray doxygen comments.
	* include/experimental/memory_resource: Likewise.
	* include/std/bit: Tweak doxygen @cond comments.
	* include/std/expected: Likewise.
	* include/std/numbers: Likewise.

libstdc++-v3/include/bits/regex.tcc

@@ -116,8 +116,6 @@ namespace __detail
   /// @endcond
 } // namespace __detail
 
-  /// @cond
-
   template<typename _Ch_type>
   template<typename _Fwd_iter>
     typename regex_traits<_Ch_type>::string_type
@@ -665,7 +663,5 @@ namespace __detail
 	_M_result = nullptr;
     }
 
-  /// @endcond
-
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace

libstdc++-v3/include/bits/uses_allocator.h

@@ -22,6 +22,11 @@
 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 // <http://www.gnu.org/licenses/>.
 
+/** @file include/bits/uses_allocator_args.h
+ *  This is an internal header file, included by other library headers.
+ *  Do not attempt to use it directly. @headername{memory}
+ */
+
 #ifndef _USES_ALLOCATOR_H
 #define _USES_ALLOCATOR_H 1
 

libstdc++-v3/include/experimental/memory_resource

@@ -45,14 +45,12 @@
 #include <bits/new_allocator.h>
 #include <debug/assertions.h>
 
-/// @cond
 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<typename _Tp> class malloc_allocator;
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace __gnu_cxx
-/// @endcond
 
 namespace std {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION

libstdc++-v3/include/std/bit

@@ -144,7 +144,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 #endif
 
-  /// @cond undoc
+  /// @cond undocumented
 
   template<typename _Tp>
     constexpr _Tp
@@ -374,7 +374,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 #define __cpp_lib_bitops 201907L
 
-  /// @cond undoc
+  /// @cond undocumented
   template<typename _Tp, typename _Up = _Tp>
     using _If_is_unsigned_integer
       = enable_if_t<__is_unsigned_integer<_Tp>::value, _Up>;

libstdc++-v3/include/std/expected

@@ -139,7 +139,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    */
   inline constexpr unexpect_t unexpect{};
 
-/// @cond undoc
+/// @cond undocumented
 namespace __expected
 {
   template<typename _Tp>
@@ -254,7 +254,7 @@ namespace __expected
 
   template<typename _Er> unexpected(_Er) -> unexpected<_Er>;
 
-/// @cond undoc
+/// @cond undocumented
 namespace __expected
 {
   template<typename _Tp>

libstdc++-v3/include/std/numbers

@@ -49,7 +49,7 @@ namespace numbers
 {
 #define __cpp_lib_math_constants 201907L
 
-  /// @cond undoc
+  /// @cond undocumented
   template<typename _Tp>
     using _Enable_if_floating = enable_if_t<is_floating_point_v<_Tp>, _Tp>;
   /// @endcond