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 23 template <class _Tp> 24 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _Tp&& 25 forward(_LIBCPP_LIFETIMEBOUND __libcpp_remove_reference_t<_Tp>& __t) _NOEXCEPT { 26 return static_cast<_Tp&&>(__t); 27 } 28 29 template <class _Tp> 30 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _Tp&& 31 forward(_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