[libc++] Merge is_scoped_enum.h into is_enum.h (#99458)

Author: philnik777

libcxx/include/CMakeLists.txt

@@ -793,7 +793,6 @@ set(files
   __type_traits/is_referenceable.h
   __type_traits/is_same.h
   __type_traits/is_scalar.h
-  __type_traits/is_scoped_enum.h
   __type_traits/is_signed.h
   __type_traits/is_signed_integer.h
   __type_traits/is_specialization.h

libcxx/include/__type_traits/is_enum.h

@@ -26,6 +26,16 @@ template <class _Tp>
 inline constexpr bool is_enum_v = __is_enum(_Tp);
 #endif
 
+#if _LIBCPP_STD_VER >= 23
+
+template <class _Tp>
+struct _LIBCPP_TEMPLATE_VIS is_scoped_enum : bool_constant<__is_scoped_enum(_Tp)> {};
+
+template <class _Tp>
+inline constexpr bool is_scoped_enum_v = __is_scoped_enum(_Tp);
+
+#endif // _LIBCPP_STD_VER >= 23
+
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___TYPE_TRAITS_IS_ENUM_H

libcxx/include/__type_traits/is_scoped_enum.h

@@ -2009,7 +2009,6 @@ module std_private_type_traits_is_scalar                                 [system
   header "__type_traits/is_scalar.h"
   export std_private_type_traits_is_null_pointer
 }
-module std_private_type_traits_is_scoped_enum                            [system] { header "__type_traits/is_scoped_enum.h" }
 module std_private_type_traits_is_signed                                 [system] { header "__type_traits/is_signed.h" }
 module std_private_type_traits_is_signed_integer                         [system] { header "__type_traits/is_signed_integer.h" }
 module std_private_type_traits_is_specialization                         [system] { header "__type_traits/is_specialization.h" }

libcxx/include/module.modulemap

@@ -514,10 +514,6 @@ namespace std
 #  include <__type_traits/unwrap_ref.h>
 #endif
 
-#if _LIBCPP_STD_VER >= 23
-#  include <__type_traits/is_scoped_enum.h>
-#endif
-
 #include <version>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)