Louis Dionne 368faacac7 [libc++] Revert "Protect users from relying on detail headers" & related changes
This commit reverts 5aaefa51 (and also partly 7f285f48e77 and b6d75682f9,
which were related to the original commit). As landed, 5aaefa51 had
unintended consequences on some downstream bots and didn't have proper
coverage upstream due to a few subtle things. Implementing this is
something we should do in libc++, however we'll first need to address
a few issues listed in https://reviews.llvm.org/D106124#3349710.

Differential Revision: https://reviews.llvm.org/D120683
2022-03-01 08:20:24 -05:00

59 lines
1.9 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___FUNCTIONAL_BIND_FRONT_H
#define _LIBCPP___FUNCTIONAL_BIND_FRONT_H
#include <__config>
#include <__functional/invoke.h>
#include <__functional/perfect_forward.h>
#include <__utility/forward.h>
#include <type_traits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER > 17
struct __bind_front_op {
template <class ..._Args>
_LIBCPP_HIDE_FROM_ABI
constexpr auto operator()(_Args&& ...__args) const
noexcept(noexcept(_VSTD::invoke(_VSTD::forward<_Args>(__args)...)))
-> decltype( _VSTD::invoke(_VSTD::forward<_Args>(__args)...))
{ return _VSTD::invoke(_VSTD::forward<_Args>(__args)...); }
};
template <class _Fn, class ..._BoundArgs>
struct __bind_front_t : __perfect_forward<__bind_front_op, _Fn, _BoundArgs...> {
using __perfect_forward<__bind_front_op, _Fn, _BoundArgs...>::__perfect_forward;
};
template <class _Fn, class... _Args, class = enable_if_t<
_And<
is_constructible<decay_t<_Fn>, _Fn>,
is_move_constructible<decay_t<_Fn>>,
is_constructible<decay_t<_Args>, _Args>...,
is_move_constructible<decay_t<_Args>>...
>::value
>>
_LIBCPP_HIDE_FROM_ABI
constexpr auto bind_front(_Fn&& __f, _Args&&... __args) {
return __bind_front_t<decay_t<_Fn>, decay_t<_Args>...>(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)...);
}
#endif // _LIBCPP_STD_VER > 17
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___FUNCTIONAL_BIND_FRONT_H