1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef _LIBCPP___CONCEPTS_CLASS_OR_ENUM_H
10 #define _LIBCPP___CONCEPTS_CLASS_OR_ENUM_H
11 
12 #include <__config>
13 #include <__type_traits/is_class.h>
14 #include <__type_traits/is_enum.h>
15 #include <__type_traits/is_union.h>
16 #include <__type_traits/remove_cvref.h>
17 
18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19 #  pragma GCC system_header
20 #endif
21 
22 _LIBCPP_BEGIN_NAMESPACE_STD
23 
24 #if _LIBCPP_STD_VER >= 20
25 
26 // Whether a type is a class type or enumeration type according to the Core wording.
27 
28 template <class _Tp>
29 concept __class_or_enum = is_class_v<_Tp> || is_union_v<_Tp> || is_enum_v<_Tp>;
30 
31 // Work around Clang bug https://llvm.org/PR52970
32 // TODO: remove this workaround once libc++ no longer has to support Clang 13 (it was fixed in Clang 14).
33 template <class _Tp>
34 concept __workaround_52970 = is_class_v<__remove_cvref_t<_Tp>> || is_union_v<__remove_cvref_t<_Tp>>;
35 
36 #endif // _LIBCPP_STD_VER >= 20
37 
38 _LIBCPP_END_NAMESPACE_STD
39 
40 #endif // _LIBCPP___CONCEPTS_CLASS_OR_ENUM_H
41