mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-02-16 03:07:54 +00:00
83 lines
3.8 KiB
C++
83 lines
3.8 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 <__type_traits/decay.h>
|
|
#include <__utility/forward.h>
|
|
#include <__utility/integer_sequence.h>
|
|
#include <tuple>
|
|
|
|
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
|
|
# pragma GCC system_header
|
|
#endif
|
|
|
|
_LIBCPP_BEGIN_NAMESPACE_STD
|
|
|
|
#if _LIBCPP_STD_VER >= 20
|
|
|
|
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 _BoundArgs, class... _Args>
|
|
_LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Fn&& __f, _BoundArgs&& __bound_args, _Args&&... __args) const
|
|
noexcept(noexcept(std::invoke(std::forward<_Fn>(__f),
|
|
std::forward<_Args>(__args)...,
|
|
std::get<_Ip>(std::forward<_BoundArgs>(__bound_args))...)))
|
|
-> decltype(std::invoke(std::forward<_Fn>(__f),
|
|
std::forward<_Args>(__args)...,
|
|
std::get<_Ip>(std::forward<_BoundArgs>(__bound_args))...)) {
|
|
return std::invoke(std::forward<_Fn>(__f),
|
|
std::forward<_Args>(__args)...,
|
|
std::get<_Ip>(std::forward<_BoundArgs>(__bound_args))...);
|
|
}
|
|
};
|
|
|
|
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>
|
|
requires is_constructible_v<decay_t<_Fn>, _Fn> && is_move_constructible_v<decay_t<_Fn>> &&
|
|
(is_constructible_v<decay_t<_Args>, _Args> && ...) && (is_move_constructible_v<decay_t<_Args>> && ...)
|
|
_LIBCPP_HIDE_FROM_ABI constexpr auto __bind_back(_Fn&& __f, _Args&&... __args) noexcept(
|
|
noexcept(__bind_back_t<decay_t<_Fn>, tuple<decay_t<_Args>...>>(
|
|
std::forward<_Fn>(__f), std::forward_as_tuple(std::forward<_Args>(__args)...))))
|
|
-> decltype(__bind_back_t<decay_t<_Fn>, tuple<decay_t<_Args>...>>(
|
|
std::forward<_Fn>(__f), std::forward_as_tuple(std::forward<_Args>(__args)...))) {
|
|
return __bind_back_t<decay_t<_Fn>, tuple<decay_t<_Args>...>>(
|
|
std::forward<_Fn>(__f), std::forward_as_tuple(std::forward<_Args>(__args)...));
|
|
}
|
|
|
|
# if _LIBCPP_STD_VER >= 23
|
|
template <class _Fn, class... _Args>
|
|
_LIBCPP_HIDE_FROM_ABI constexpr auto bind_back(_Fn&& __f, _Args&&... __args) {
|
|
static_assert(is_constructible_v<decay_t<_Fn>, _Fn>, "bind_back requires decay_t<F> to be constructible from F");
|
|
static_assert(is_move_constructible_v<decay_t<_Fn>>, "bind_back requires decay_t<F> to be move constructible");
|
|
static_assert((is_constructible_v<decay_t<_Args>, _Args> && ...),
|
|
"bind_back requires all decay_t<Args> to be constructible from respective Args");
|
|
static_assert((is_move_constructible_v<decay_t<_Args>> && ...),
|
|
"bind_back requires all decay_t<Args> to be move constructible");
|
|
return __bind_back_t<decay_t<_Fn>, tuple<decay_t<_Args>...>>(
|
|
std::forward<_Fn>(__f), std::forward_as_tuple(std::forward<_Args>(__args)...));
|
|
}
|
|
# endif // _LIBCPP_STD_VER >= 23
|
|
|
|
#endif // _LIBCPP_STD_VER >= 20
|
|
|
|
_LIBCPP_END_NAMESPACE_STD
|
|
|
|
#endif // _LIBCPP___FUNCTIONAL_BIND_BACK_H
|