compare_three_way.h 1.2 KB

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  1. // -*- C++ -*-
  2. //===----------------------------------------------------------------------===//
  3. //
  4. // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  5. // See https://llvm.org/LICENSE.txt for license information.
  6. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  7. //
  8. //===----------------------------------------------------------------------===//
  9. #ifndef _LIBCPP___COMPARE_COMPARE_THREE_WAY_H
  10. #define _LIBCPP___COMPARE_COMPARE_THREE_WAY_H
  11. #include <__compare/three_way_comparable.h>
  12. #include <__config>
  13. #include <__utility/forward.h>
  14. #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  15. # pragma GCC system_header
  16. #endif
  17. _LIBCPP_BEGIN_NAMESPACE_STD
  18. #if _LIBCPP_STD_VER >= 20
  19. struct _LIBCPP_TEMPLATE_VIS compare_three_way {
  20. template <class _T1, class _T2>
  21. requires three_way_comparable_with<_T1, _T2>
  22. constexpr _LIBCPP_HIDE_FROM_ABI auto operator()(_T1&& __t, _T2&& __u) const
  23. noexcept(noexcept(std::forward<_T1>(__t) <=> std::forward<_T2>(__u))) {
  24. return std::forward<_T1>(__t) <=> std::forward<_T2>(__u);
  25. }
  26. using is_transparent = void;
  27. };
  28. #endif // _LIBCPP_STD_VER >= 20
  29. _LIBCPP_END_NAMESPACE_STD
  30. #endif // _LIBCPP___COMPARE_COMPARE_THREE_WAY_H