forward.h revision 1.1.1.1 
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>
15
16#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
17#pragma GCC system_header
18#endif
19
20_LIBCPP_PUSH_MACROS
21#include <__undef_macros>
22
23_LIBCPP_BEGIN_NAMESPACE_STD
24
25template <class _Tp>
26_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR _Tp&&
27forward(typename remove_reference<_Tp>::type& __t) _NOEXCEPT {
28  return static_cast<_Tp&&>(__t);
29}
30
31template <class _Tp>
32_LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR _Tp&&
33forward(typename remove_reference<_Tp>::type&& __t) _NOEXCEPT {
34  static_assert(!is_lvalue_reference<_Tp>::value, "cannot forward an rvalue as an lvalue");
35  return static_cast<_Tp&&>(__t);
36}
37
38_LIBCPP_END_NAMESPACE_STD
39
40_LIBCPP_POP_MACROS
41
42#endif // _LIBCPP___UTILITY_FORWARD_H
43