libcxx/include/__concepts/class_or_enum.h

   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>
  14
  15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  16 #pragma GCC system_header
  17 #endif
  18
  19 _LIBCPP_BEGIN_NAMESPACE_STD
  20
  21 #if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
  22
  23 // Whether a type is a class type or enumeration type according to the Core wording.
  24
  25 template<class _Tp>
  26 concept __class_or_enum = is_class_v<_Tp> || is_union_v<_Tp> || is_enum_v<_Tp>;
  27
  28 // Work around Clang bug https://llvm.org/PR52970
  29 template<class _Tp>
  30 concept __workaround_52970 = is_class_v<__uncvref_t<_Tp>> || is_union_v<__uncvref_t<_Tp>>;
  31
  32 #endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
  33
  34 _LIBCPP_END_NAMESPACE_STD
  35
  36 #endif // _LIBCPP___CONCEPTS_CLASS_OR_ENUM_H