llvm-project/libcxx/include/__functional/bind_back.h

66 lines
2.8 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_BACK_H
#define _LIBCPP___FUNCTIONAL_BIND_BACK_H
#include <__config>
#include <__functional/invoke.h>
#include <__functional/perfect_forward.h>
#include <__utility/forward.h>
#include <__utility/integer_sequence.h>
#include <tuple>
#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
template <size_t _NBound, class = make_index_sequence<_NBound>>
struct __bind_back_op;
template <size_t _NBound, size_t ..._Ip>
struct __bind_back_op<_NBound, index_sequence<_Ip...>> {
template <class _Fn, class _Bound, class ..._Args>
_LIBCPP_HIDE_FROM_ABI
constexpr auto operator()(_Fn&& __f, _Bound&& __bound, _Args&& ...__args) const
noexcept(noexcept(_VSTD::invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)..., _VSTD::get<_Ip>(_VSTD::forward<_Bound>(__bound))...)))
-> decltype( _VSTD::invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)..., _VSTD::get<_Ip>(_VSTD::forward<_Bound>(__bound))...))
{ return _VSTD::invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)..., _VSTD::get<_Ip>(_VSTD::forward<_Bound>(__bound))...); }
};
template <class _Fn, class _BoundArgs>
struct __bind_back_t : __perfect_forward<__bind_back_op<tuple_size_v<_BoundArgs>>, _Fn, _BoundArgs> {
using __perfect_forward<__bind_back_op<tuple_size_v<_BoundArgs>>, _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_back(_Fn&& __f, _Args&&... __args)
noexcept(noexcept(__bind_back_t<decay_t<_Fn>, tuple<decay_t<_Args>...>>(_VSTD::forward<_Fn>(__f), _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...))))
-> decltype( __bind_back_t<decay_t<_Fn>, tuple<decay_t<_Args>...>>(_VSTD::forward<_Fn>(__f), _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)))
{ return __bind_back_t<decay_t<_Fn>, tuple<decay_t<_Args>...>>(_VSTD::forward<_Fn>(__f), _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)); }
#endif // _LIBCPP_STD_VER > 17
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___FUNCTIONAL_BIND_BACK_H