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_FRONT_H 11 #define _LIBCPP___FUNCTIONAL_BIND_FRONT_H 12 13 #include <__config> 14 #include <__functional/perfect_forward.h> 15 #include <__functional/invoke.h> 16 #include <type_traits> 17 #include <utility> 18 19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 20 #pragma GCC system_header 21 #endif 22 23 _LIBCPP_BEGIN_NAMESPACE_STD 24 25 #if _LIBCPP_STD_VER > 17 26 27 struct __bind_front_op 28 { 29 template<class... _Args> 30 constexpr static auto __call(_Args&&... __args) 31 noexcept(noexcept(_VSTD::invoke(_VSTD::forward<_Args>(__args)...))) 32 -> decltype( _VSTD::invoke(_VSTD::forward<_Args>(__args)...)) 33 { return _VSTD::invoke(_VSTD::forward<_Args>(__args)...); } 34 }; 35 36 template<class _Fn, class... _Args, 37 class = _EnableIf<conjunction<is_constructible<decay_t<_Fn>, _Fn>, 38 is_move_constructible<decay_t<_Fn>>, 39 is_constructible<decay_t<_Args>, _Args>..., 40 is_move_constructible<decay_t<_Args>>... 41 >::value>> 42 constexpr auto bind_front(_Fn&& __f, _Args&&... __args) 43 { 44 return __perfect_forward<__bind_front_op, _Fn, _Args...>(_VSTD::forward<_Fn>(__f), 45 _VSTD::forward<_Args>(__args)...); 46 } 47 48 #endif // _LIBCPP_STD_VER > 17 49 50 _LIBCPP_END_NAMESPACE_STD 51 52 #endif // _LIBCPP___FUNCTIONAL_BIND_FRONT_H 53