1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___TYPE_TRAITS_IS_ASSIGNABLE_H 10 #define _LIBCPP___TYPE_TRAITS_IS_ASSIGNABLE_H 11 12 #include <__config> 13 #include <__type_traits/add_lvalue_reference.h> 14 #include <__type_traits/add_rvalue_reference.h> 15 #include <__type_traits/integral_constant.h> 16 17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 18 # pragma GCC system_header 19 #endif 20 21 _LIBCPP_BEGIN_NAMESPACE_STD 22 23 template <class _Tp, class _Up> 24 struct _LIBCPP_TEMPLATE_VIS is_assignable : _BoolConstant<__is_assignable(_Tp, _Up)> {}; 25 26 #if _LIBCPP_STD_VER >= 17 27 template <class _Tp, class _Arg> 28 inline constexpr bool is_assignable_v = __is_assignable(_Tp, _Arg); 29 #endif 30 31 template <class _Tp> 32 struct _LIBCPP_TEMPLATE_VIS is_copy_assignable 33 : public integral_constant<bool, 34 __is_assignable(__add_lvalue_reference_t<_Tp>, __add_lvalue_reference_t<const _Tp>)> {}; 35 36 #if _LIBCPP_STD_VER >= 17 37 template <class _Tp> 38 inline constexpr bool is_copy_assignable_v = is_copy_assignable<_Tp>::value; 39 #endif 40 41 template <class _Tp> 42 struct _LIBCPP_TEMPLATE_VIS is_move_assignable 43 : public integral_constant<bool, __is_assignable(__add_lvalue_reference_t<_Tp>, __add_rvalue_reference_t<_Tp>)> {}; 44 45 #if _LIBCPP_STD_VER >= 17 46 template <class _Tp> 47 inline constexpr bool is_move_assignable_v = is_move_assignable<_Tp>::value; 48 #endif 49 50 _LIBCPP_END_NAMESPACE_STD 51 52 #endif // _LIBCPP___TYPE_TRAITS_IS_ASSIGNABLE_H 53