[libc++] Merge is_member{,_object,_function}_pointer.h (#98727)

The implementations for these traits have been simplified quite a bit,
since we have builtins available for them now.

Author: philnik777

libcxx/include/CMakeLists.txt

@@ -777,8 +777,6 @@ set(files
   __type_traits/is_implicitly_default_constructible.h
   __type_traits/is_integral.h
   __type_traits/is_literal_type.h
-  __type_traits/is_member_function_pointer.h
-  __type_traits/is_member_object_pointer.h
   __type_traits/is_member_pointer.h
   __type_traits/is_nothrow_assignable.h
   __type_traits/is_nothrow_constructible.h

libcxx/include/__type_traits/invoke.h

@@ -17,8 +17,7 @@
 #include <__type_traits/integral_constant.h>
 #include <__type_traits/is_base_of.h>
 #include <__type_traits/is_core_convertible.h>
-#include <__type_traits/is_member_function_pointer.h>
-#include <__type_traits/is_member_object_pointer.h>
+#include <__type_traits/is_member_pointer.h>
 #include <__type_traits/is_reference_wrapper.h>
 #include <__type_traits/is_same.h>
 #include <__type_traits/is_void.h>

libcxx/include/__type_traits/is_member_function_pointer.h

@@ -21,9 +21,21 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 template <class _Tp>
 struct _LIBCPP_TEMPLATE_VIS is_member_pointer : _BoolConstant<__is_member_pointer(_Tp)> {};
 
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_member_object_pointer : _BoolConstant<__is_member_object_pointer(_Tp)> {};
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_member_function_pointer : _BoolConstant<__is_member_function_pointer(_Tp)> {};
+
 #  if _LIBCPP_STD_VER >= 17
 template <class _Tp>
 inline constexpr bool is_member_pointer_v = __is_member_pointer(_Tp);
+
+template <class _Tp>
+inline constexpr bool is_member_object_pointer_v = __is_member_object_pointer(_Tp);
+
+template <class _Tp>
+inline constexpr bool is_member_function_pointer_v = __is_member_function_pointer(_Tp);
 #  endif
 
 _LIBCPP_END_NAMESPACE_STD

libcxx/include/__type_traits/is_member_object_pointer.h

@@ -1962,8 +1962,6 @@ module std_private_type_traits_is_fundamental                            [system
 module std_private_type_traits_is_implicitly_default_constructible       [system] { header "__type_traits/is_implicitly_default_constructible.h" }
 module std_private_type_traits_is_integral                               [system] { header "__type_traits/is_integral.h" }
 module std_private_type_traits_is_literal_type                           [system] { header "__type_traits/is_literal_type.h" }
-module std_private_type_traits_is_member_function_pointer                [system] { header "__type_traits/is_member_function_pointer.h" }
-module std_private_type_traits_is_member_object_pointer                  [system] { header "__type_traits/is_member_object_pointer.h" }
 module std_private_type_traits_is_member_pointer                         [system] { header "__type_traits/is_member_pointer.h" }
 module std_private_type_traits_is_nothrow_assignable                     [system] { header "__type_traits/is_nothrow_assignable.h" }
 module std_private_type_traits_is_nothrow_constructible                  [system] {

libcxx/include/__type_traits/is_member_pointer.h

@@ -467,8 +467,6 @@ namespace std
 #include <__type_traits/is_implicitly_default_constructible.h>
 #include <__type_traits/is_integral.h>
 #include <__type_traits/is_literal_type.h>
-#include <__type_traits/is_member_function_pointer.h>
-#include <__type_traits/is_member_object_pointer.h>
 #include <__type_traits/is_member_pointer.h>
 #include <__type_traits/is_nothrow_assignable.h>
 #include <__type_traits/is_nothrow_constructible.h>