forward.h revision 1.1.1.2
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 10#ifndef _LIBCPP___UTILITY_FORWARD_H 11#define _LIBCPP___UTILITY_FORWARD_H 12 13#include <__config> 14#include <__type_traits/is_reference.h> 15#include <__type_traits/remove_reference.h> 16 17#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 18# pragma GCC system_header 19#endif 20 21_LIBCPP_BEGIN_NAMESPACE_STD 22 23template <class _Tp> 24_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _Tp&& 25forward(_LIBCPP_LIFETIMEBOUND __libcpp_remove_reference_t<_Tp>& __t) _NOEXCEPT { 26 return static_cast<_Tp&&>(__t); 27} 28 29template <class _Tp> 30_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _Tp&& 31forward(_LIBCPP_LIFETIMEBOUND __libcpp_remove_reference_t<_Tp>&& __t) _NOEXCEPT { 32 static_assert(!is_lvalue_reference<_Tp>::value, "cannot forward an rvalue as an lvalue"); 33 return static_cast<_Tp&&>(__t); 34} 35 36_LIBCPP_END_NAMESPACE_STD 37 38#endif // _LIBCPP___UTILITY_FORWARD_H 39