to_underlying.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___UTILITY_TO_UNDERLYING_H
  10. #define _LIBCPP___UTILITY_TO_UNDERLYING_H
  11. #include <__config>
  12. #include <__type_traits/underlying_type.h>
  13. #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  14. # pragma GCC system_header
  15. #endif
  16. _LIBCPP_BEGIN_NAMESPACE_STD
  17. #ifndef _LIBCPP_CXX03_LANG
  18. template <class _Tp>
  19. _LIBCPP_HIDE_FROM_ABI constexpr typename underlying_type<_Tp>::type __to_underlying(_Tp __val) noexcept {
  20. return static_cast<typename underlying_type<_Tp>::type>(__val);
  21. }
  22. #endif // !_LIBCPP_CXX03_LANG
  23. #if _LIBCPP_STD_VER >= 23
  24. template <class _Tp>
  25. _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr underlying_type_t<_Tp> to_underlying(_Tp __val) noexcept {
  26. return std::__to_underlying(__val);
  27. }
  28. #endif
  29. _LIBCPP_END_NAMESPACE_STD
  30. #endif // _LIBCPP___UTILITY_TO_UNDERLYING_H