1349cc55cSDimitry Andric // -*- C++ -*- 2349cc55cSDimitry Andric //===----------------------------------------------------------------------===// 3349cc55cSDimitry Andric // 4349cc55cSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5349cc55cSDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 6349cc55cSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7349cc55cSDimitry Andric // 8349cc55cSDimitry Andric //===----------------------------------------------------------------------===// 9349cc55cSDimitry Andric 10349cc55cSDimitry Andric #ifndef _LIBCPP___FUNCTIONAL_BIND_BACK_H 11349cc55cSDimitry Andric #define _LIBCPP___FUNCTIONAL_BIND_BACK_H 12349cc55cSDimitry Andric 13349cc55cSDimitry Andric #include <__config> 14349cc55cSDimitry Andric #include <__functional/invoke.h> 15349cc55cSDimitry Andric #include <__functional/perfect_forward.h> 1606c3fb27SDimitry Andric #include <__type_traits/decay.h> 17349cc55cSDimitry Andric #include <__utility/forward.h> 18349cc55cSDimitry Andric #include <__utility/integer_sequence.h> 19349cc55cSDimitry Andric #include <tuple> 20349cc55cSDimitry Andric 21349cc55cSDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 22349cc55cSDimitry Andric # pragma GCC system_header 23349cc55cSDimitry Andric #endif 24349cc55cSDimitry Andric 25349cc55cSDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD 26349cc55cSDimitry Andric 2706c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20 28349cc55cSDimitry Andric 29349cc55cSDimitry Andric template <size_t _NBound, class = make_index_sequence<_NBound>> 30349cc55cSDimitry Andric struct __bind_back_op; 31349cc55cSDimitry Andric 32349cc55cSDimitry Andric template <size_t _NBound, size_t... _Ip> 33349cc55cSDimitry Andric struct __bind_back_op<_NBound, index_sequence<_Ip...>> { 3481ad6265SDimitry Andric template <class _Fn, class _BoundArgs, class... _Args> 3581ad6265SDimitry Andric _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Fn&& __f, _BoundArgs&& __bound_args, _Args&&... __args) const 36*cb14a3feSDimitry Andric noexcept(noexcept(std::invoke(std::forward<_Fn>(__f), 37*cb14a3feSDimitry Andric std::forward<_Args>(__args)..., 38*cb14a3feSDimitry Andric std::get<_Ip>(std::forward<_BoundArgs>(__bound_args))...))) 39*cb14a3feSDimitry Andric -> decltype(std::invoke(std::forward<_Fn>(__f), 40*cb14a3feSDimitry Andric std::forward<_Args>(__args)..., 41*cb14a3feSDimitry Andric std::get<_Ip>(std::forward<_BoundArgs>(__bound_args))...)) { 42*cb14a3feSDimitry Andric return std::invoke(std::forward<_Fn>(__f), 43*cb14a3feSDimitry Andric std::forward<_Args>(__args)..., 44*cb14a3feSDimitry Andric std::get<_Ip>(std::forward<_BoundArgs>(__bound_args))...); 45*cb14a3feSDimitry Andric } 46349cc55cSDimitry Andric }; 47349cc55cSDimitry Andric 48349cc55cSDimitry Andric template <class _Fn, class _BoundArgs> 49349cc55cSDimitry Andric struct __bind_back_t : __perfect_forward<__bind_back_op<tuple_size_v<_BoundArgs>>, _Fn, _BoundArgs> { 50349cc55cSDimitry Andric using __perfect_forward<__bind_back_op<tuple_size_v<_BoundArgs>>, _Fn, _BoundArgs>::__perfect_forward; 51349cc55cSDimitry Andric }; 52349cc55cSDimitry Andric 535f757f3fSDimitry Andric template <class _Fn, class... _Args> 545f757f3fSDimitry Andric requires is_constructible_v<decay_t<_Fn>, _Fn> && is_move_constructible_v<decay_t<_Fn>> && 555f757f3fSDimitry Andric (is_constructible_v<decay_t<_Args>, _Args> && ...) && (is_move_constructible_v<decay_t<_Args>> && ...) 56*cb14a3feSDimitry Andric _LIBCPP_HIDE_FROM_ABI constexpr auto __bind_back(_Fn&& __f, _Args&&... __args) noexcept( 57*cb14a3feSDimitry Andric noexcept(__bind_back_t<decay_t<_Fn>, tuple<decay_t<_Args>...>>( 58*cb14a3feSDimitry Andric std::forward<_Fn>(__f), std::forward_as_tuple(std::forward<_Args>(__args)...)))) 59*cb14a3feSDimitry Andric -> decltype(__bind_back_t<decay_t<_Fn>, tuple<decay_t<_Args>...>>( 60*cb14a3feSDimitry Andric std::forward<_Fn>(__f), std::forward_as_tuple(std::forward<_Args>(__args)...))) { 61*cb14a3feSDimitry Andric return __bind_back_t<decay_t<_Fn>, tuple<decay_t<_Args>...>>( 62*cb14a3feSDimitry Andric std::forward<_Fn>(__f), std::forward_as_tuple(std::forward<_Args>(__args)...)); 63*cb14a3feSDimitry Andric } 64349cc55cSDimitry Andric 6506c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20 66349cc55cSDimitry Andric 67349cc55cSDimitry Andric _LIBCPP_END_NAMESPACE_STD 68349cc55cSDimitry Andric 69349cc55cSDimitry Andric #endif // _LIBCPP___FUNCTIONAL_BIND_BACK_H 70