1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef _LIBCPP___FUNCTIONAL_BIND_BACK_H 11 #define _LIBCPP___FUNCTIONAL_BIND_BACK_H 12 13 #include <__config> 14 #include <__functional/invoke.h> 15 #include <__functional/perfect_forward.h> 16 #include <__utility/forward.h> 17 #include <__utility/integer_sequence.h> 18 #include <tuple> 19 #include <type_traits> 20 21 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 22 # pragma GCC system_header 23 #endif 24 25 _LIBCPP_BEGIN_NAMESPACE_STD 26 27 #if _LIBCPP_STD_VER > 17 28 29 template <size_t _NBound, class = make_index_sequence<_NBound>> 30 struct __bind_back_op; 31 32 template <size_t _NBound, size_t ..._Ip> 33 struct __bind_back_op<_NBound, index_sequence<_Ip...>> { 34 template <class _Fn, class _BoundArgs, class... _Args> 35 _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Fn&& __f, _BoundArgs&& __bound_args, _Args&&... __args) const 36 noexcept(noexcept(_VSTD::invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)..., _VSTD::get<_Ip>(_VSTD::forward<_BoundArgs>(__bound_args))...))) 37 -> decltype( _VSTD::invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)..., _VSTD::get<_Ip>(_VSTD::forward<_BoundArgs>(__bound_args))...)) 38 { return _VSTD::invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)..., _VSTD::get<_Ip>(_VSTD::forward<_BoundArgs>(__bound_args))...); } 39 }; 40 41 template <class _Fn, class _BoundArgs> 42 struct __bind_back_t : __perfect_forward<__bind_back_op<tuple_size_v<_BoundArgs>>, _Fn, _BoundArgs> { 43 using __perfect_forward<__bind_back_op<tuple_size_v<_BoundArgs>>, _Fn, _BoundArgs>::__perfect_forward; 44 }; 45 46 template <class _Fn, class ..._Args, class = enable_if_t< 47 _And< 48 is_constructible<decay_t<_Fn>, _Fn>, 49 is_move_constructible<decay_t<_Fn>>, 50 is_constructible<decay_t<_Args>, _Args>..., 51 is_move_constructible<decay_t<_Args>>... 52 >::value 53 >> 54 _LIBCPP_HIDE_FROM_ABI 55 constexpr auto __bind_back(_Fn&& __f, _Args&&... __args) 56 noexcept(noexcept(__bind_back_t<decay_t<_Fn>, tuple<decay_t<_Args>...>>(_VSTD::forward<_Fn>(__f), _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)))) 57 -> decltype( __bind_back_t<decay_t<_Fn>, tuple<decay_t<_Args>...>>(_VSTD::forward<_Fn>(__f), _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...))) 58 { return __bind_back_t<decay_t<_Fn>, tuple<decay_t<_Args>...>>(_VSTD::forward<_Fn>(__f), _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)); } 59 60 #endif // _LIBCPP_STD_VER > 17 61 62 _LIBCPP_END_NAMESPACE_STD 63 64 #endif // _LIBCPP___FUNCTIONAL_BIND_BACK_H 65