as_const.h 972 B

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  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. #ifndef _LIBCPP___UTILITY_AS_CONST_H
  9. #define _LIBCPP___UTILITY_AS_CONST_H
  10. #include <__config>
  11. #include <__type_traits/add_const.h>
  12. #include <__utility/forward.h>
  13. #include <__utility/move.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 > 14
  19. template <class _Tp>
  20. _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { return __t; }
  21. template <class _Tp>
  22. void as_const(const _Tp&&) = delete;
  23. #endif
  24. _LIBCPP_END_NAMESPACE_STD
  25. #endif // _LIBCPP___UTILITY_AS_CONST_H