libcxx/include/__concepts/same_as.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_SAME_AS_H
  10 #define _LIBCPP___CONCEPTS_SAME_AS_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 // [concept.same]
  24
  25 template<class _Tp, class _Up>
  26 concept __same_as_impl = _IsSame<_Tp, _Up>::value;
  27
  28 template<class _Tp, class _Up>
  29 concept same_as = __same_as_impl<_Tp, _Up> && __same_as_impl<_Up, _Tp>;
  30
  31 #endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
  32
  33 _LIBCPP_END_NAMESPACE_STD
  34
  35 #endif // _LIBCPP___CONCEPTS_SAME_AS_H