1*4bdff4beSrobert //===----------------------------------------------------------------------===// 2*4bdff4beSrobert // 3*4bdff4beSrobert // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*4bdff4beSrobert // See https://llvm.org/LICENSE.txt for license information. 5*4bdff4beSrobert // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*4bdff4beSrobert // 7*4bdff4beSrobert //===----------------------------------------------------------------------===// 8*4bdff4beSrobert 9*4bdff4beSrobert #ifndef _LIBCPP___CONCEPTS_ASSIGNABLE_H 10*4bdff4beSrobert #define _LIBCPP___CONCEPTS_ASSIGNABLE_H 11*4bdff4beSrobert 12*4bdff4beSrobert #include <__concepts/common_reference_with.h> 13*4bdff4beSrobert #include <__concepts/same_as.h> 14*4bdff4beSrobert #include <__config> 15*4bdff4beSrobert #include <__type_traits/is_reference.h> 16*4bdff4beSrobert #include <__type_traits/make_const_lvalue_ref.h> 17*4bdff4beSrobert #include <__utility/forward.h> 18*4bdff4beSrobert 19*4bdff4beSrobert #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 20*4bdff4beSrobert # pragma GCC system_header 21*4bdff4beSrobert #endif 22*4bdff4beSrobert 23*4bdff4beSrobert _LIBCPP_BEGIN_NAMESPACE_STD 24*4bdff4beSrobert 25*4bdff4beSrobert #if _LIBCPP_STD_VER > 17 26*4bdff4beSrobert 27*4bdff4beSrobert // [concept.assignable] 28*4bdff4beSrobert 29*4bdff4beSrobert template<class _Lhs, class _Rhs> 30*4bdff4beSrobert concept assignable_from = 31*4bdff4beSrobert is_lvalue_reference_v<_Lhs> && 32*4bdff4beSrobert common_reference_with<__make_const_lvalue_ref<_Lhs>, __make_const_lvalue_ref<_Rhs>> && requires(_Lhs __lhs,_Rhs && __rhs)33*4bdff4beSrobert requires (_Lhs __lhs, _Rhs&& __rhs) { 34*4bdff4beSrobert { __lhs = _VSTD::forward<_Rhs>(__rhs) } -> same_as<_Lhs>; 35*4bdff4beSrobert }; 36*4bdff4beSrobert 37*4bdff4beSrobert #endif // _LIBCPP_STD_VER > 17 38*4bdff4beSrobert 39*4bdff4beSrobert _LIBCPP_END_NAMESPACE_STD 40*4bdff4beSrobert 41*4bdff4beSrobert #endif // _LIBCPP___CONCEPTS_ASSIGNABLE_H 42