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_NOTHROW_ASSIGNABLE_H 10 #define _LIBCPP___TYPE_TRAITS_IS_NOTHROW_ASSIGNABLE_H 11 12 #include <__config> 13 #include <__type_traits/add_const.h> 14 #include <__type_traits/integral_constant.h> 15 16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17 # pragma GCC system_header 18 #endif 19 20 _LIBCPP_BEGIN_NAMESPACE_STD 21 22 #if __has_builtin(__is_nothrow_assignable) 23 24 template <class _Tp, class _Arg> 25 struct _LIBCPP_TEMPLATE_VIS is_nothrow_assignable 26 : public integral_constant<bool, __is_nothrow_assignable(_Tp, _Arg)> {}; 27 28 #else 29 30 template <bool, class _Tp, class _Arg> struct __libcpp_is_nothrow_assignable; 31 32 template <class _Tp, class _Arg> 33 struct __libcpp_is_nothrow_assignable<false, _Tp, _Arg> 34 : public false_type 35 { 36 }; 37 38 template <class _Tp, class _Arg> 39 struct __libcpp_is_nothrow_assignable<true, _Tp, _Arg> 40 : public integral_constant<bool, noexcept(declval<_Tp>() = declval<_Arg>()) > 41 { 42 }; 43 44 template <class _Tp, class _Arg> 45 struct _LIBCPP_TEMPLATE_VIS is_nothrow_assignable 46 : public __libcpp_is_nothrow_assignable<is_assignable<_Tp, _Arg>::value, _Tp, _Arg> 47 { 48 }; 49 50 #endif // __has_builtin(__is_nothrow_assignable) 51 52 #if _LIBCPP_STD_VER > 14 53 template <class _Tp, class _Arg> 54 inline constexpr bool is_nothrow_assignable_v = is_nothrow_assignable<_Tp, _Arg>::value; 55 #endif 56 57 _LIBCPP_END_NAMESPACE_STD 58 59 #endif // _LIBCPP___TYPE_TRAITS_IS_NOTHROW_ASSIGNABLE_H 60