forward.h 1.1 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_FORWARD_H
  10. #define _LIBCPP___UTILITY_FORWARD_H
  11. #include <__config>
  12. #include <type_traits>
  13. #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  14. # pragma GCC system_header
  15. #endif
  16. _LIBCPP_BEGIN_NAMESPACE_STD
  17. template <class _Tp>
  18. _LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR _Tp&&
  19. forward(typename remove_reference<_Tp>::type& __t) _NOEXCEPT {
  20. return static_cast<_Tp&&>(__t);
  21. }
  22. template <class _Tp>
  23. _LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR _Tp&&
  24. forward(typename remove_reference<_Tp>::type&& __t) _NOEXCEPT {
  25. static_assert(!is_lvalue_reference<_Tp>::value, "cannot forward an rvalue as an lvalue");
  26. return static_cast<_Tp&&>(__t);
  27. }
  28. _LIBCPP_END_NAMESPACE_STD
  29. #endif // _LIBCPP___UTILITY_FORWARD_H