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_CONSTRUCTIBLE_H 10 #define _LIBCPP___TYPE_TRAITS_IS_NOTHROW_CONSTRUCTIBLE_H 11 12 #include <__config> 13 #include <__type_traits/integral_constant.h> 14 #include <__utility/declval.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_constructible) 23 24 template <class _Tp, class... _Args> 25 struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible 26 : public integral_constant<bool, __is_nothrow_constructible(_Tp, _Args...)> {}; 27 28 #else 29 30 template <bool, bool, class _Tp, class... _Args> struct __libcpp_is_nothrow_constructible; 31 32 template <class _Tp, class... _Args> 33 struct __libcpp_is_nothrow_constructible</*is constructible*/true, /*is reference*/false, _Tp, _Args...> 34 : public integral_constant<bool, noexcept(_Tp(declval<_Args>()...))> 35 { 36 }; 37 38 template <class _Tp> 39 void __implicit_conversion_to(_Tp) noexcept { } 40 41 template <class _Tp, class _Arg> 42 struct __libcpp_is_nothrow_constructible</*is constructible*/true, /*is reference*/true, _Tp, _Arg> 43 : public integral_constant<bool, noexcept(_VSTD::__implicit_conversion_to<_Tp>(declval<_Arg>()))> 44 { 45 }; 46 47 template <class _Tp, bool _IsReference, class... _Args> 48 struct __libcpp_is_nothrow_constructible</*is constructible*/false, _IsReference, _Tp, _Args...> 49 : public false_type 50 { 51 }; 52 53 template <class _Tp, class... _Args> 54 struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible 55 : __libcpp_is_nothrow_constructible<is_constructible<_Tp, _Args...>::value, is_reference<_Tp>::value, _Tp, _Args...> 56 { 57 }; 58 59 template <class _Tp, size_t _Ns> 60 struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible<_Tp[_Ns]> 61 : __libcpp_is_nothrow_constructible<is_constructible<_Tp>::value, is_reference<_Tp>::value, _Tp> 62 { 63 }; 64 65 #endif // __has_builtin(__is_nothrow_constructible) 66 67 68 #if _LIBCPP_STD_VER > 14 69 template <class _Tp, class ..._Args> 70 inline constexpr bool is_nothrow_constructible_v = is_nothrow_constructible<_Tp, _Args...>::value; 71 #endif 72 73 _LIBCPP_END_NAMESPACE_STD 74 75 #endif // _LIBCPP___TYPE_TRAITS_IS_NOTHROW_CONSTRUCTIBLE_H 76