xref: /freebsd/contrib/llvm-project/libcxx/include/__utility/forward.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1fe6060f1SDimitry Andric // -*- C++ -*-
2fe6060f1SDimitry Andric //===----------------------------------------------------------------------===//
3fe6060f1SDimitry Andric //
4fe6060f1SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5fe6060f1SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
6fe6060f1SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7fe6060f1SDimitry Andric //
8fe6060f1SDimitry Andric //===----------------------------------------------------------------------===//
9fe6060f1SDimitry Andric 
10fe6060f1SDimitry Andric #ifndef _LIBCPP___UTILITY_FORWARD_H
11fe6060f1SDimitry Andric #define _LIBCPP___UTILITY_FORWARD_H
12fe6060f1SDimitry Andric 
13fe6060f1SDimitry Andric #include <__config>
1481ad6265SDimitry Andric #include <__type_traits/is_reference.h>
1581ad6265SDimitry Andric #include <__type_traits/remove_reference.h>
16fe6060f1SDimitry Andric 
17fe6060f1SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18fe6060f1SDimitry Andric #  pragma GCC system_header
19fe6060f1SDimitry Andric #endif
20fe6060f1SDimitry Andric 
21fe6060f1SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
22fe6060f1SDimitry Andric 
23fe6060f1SDimitry Andric template <class _Tp>
24*0fca6ea1SDimitry Andric _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _Tp&&
forward(_LIBCPP_LIFETIMEBOUND __libcpp_remove_reference_t<_Tp> & __t)25bdd1243dSDimitry Andric forward(_LIBCPP_LIFETIMEBOUND __libcpp_remove_reference_t<_Tp>& __t) _NOEXCEPT {
26fe6060f1SDimitry Andric   return static_cast<_Tp&&>(__t);
27fe6060f1SDimitry Andric }
28fe6060f1SDimitry Andric 
29fe6060f1SDimitry Andric template <class _Tp>
30*0fca6ea1SDimitry Andric _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _Tp&&
forward(_LIBCPP_LIFETIMEBOUND __libcpp_remove_reference_t<_Tp> && __t)31bdd1243dSDimitry Andric forward(_LIBCPP_LIFETIMEBOUND __libcpp_remove_reference_t<_Tp>&& __t) _NOEXCEPT {
32fe6060f1SDimitry Andric   static_assert(!is_lvalue_reference<_Tp>::value, "cannot forward an rvalue as an lvalue");
33fe6060f1SDimitry Andric   return static_cast<_Tp&&>(__t);
34fe6060f1SDimitry Andric }
35fe6060f1SDimitry Andric 
36fe6060f1SDimitry Andric _LIBCPP_END_NAMESPACE_STD
37fe6060f1SDimitry Andric 
38fe6060f1SDimitry Andric #endif // _LIBCPP___UTILITY_FORWARD_H
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