llvm-capstone/libcxx/include/__utility/forward.h
Nikolas Klauser 277a9f6e5f [libc++] Add [[clang::lifetimebound]] attribute to std::forward and friends
This allows clang to catch lifetime bugs through these functions.
As a drive-by, replace `_LIBCPP_INLINE_VISIBILITY` with `_LIBCPP_HIDE_FROM_ABI`.
Fixes #59900

Reviewed By: ldionne, #libc

Spies: rsmith, rnk, aaron.ballman, libcxx-commits

Differential Revision: https://reviews.llvm.org/D141321
2023-01-14 02:54:33 +01:00

39 lines
1.2 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___UTILITY_FORWARD_H
#define _LIBCPP___UTILITY_FORWARD_H
#include <__config>
#include <__type_traits/is_reference.h>
#include <__type_traits/remove_reference.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
template <class _Tp>
_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _Tp&&
forward(_LIBCPP_LIFETIMEBOUND __libcpp_remove_reference_t<_Tp>& __t) _NOEXCEPT {
return static_cast<_Tp&&>(__t);
}
template <class _Tp>
_LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _Tp&&
forward(_LIBCPP_LIFETIMEBOUND __libcpp_remove_reference_t<_Tp>&& __t) _NOEXCEPT {
static_assert(!is_lvalue_reference<_Tp>::value, "cannot forward an rvalue as an lvalue");
return static_cast<_Tp&&>(__t);
}
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___UTILITY_FORWARD_H