xref: /freebsd/contrib/llvm-project/libcxx/include/__type_traits/is_nothrow_constructible.h (revision 2f2ebe758bea201830bd021525424813f7fc6c6b)
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/add_lvalue_reference.h>
14 #include <__type_traits/add_rvalue_reference.h>
15 #include <__type_traits/integral_constant.h>
16 #include <__type_traits/is_constructible.h>
17 #include <__type_traits/is_reference.h>
18 #include <__utility/declval.h>
19 #include <cstddef>
20 
21 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
22 #  pragma GCC system_header
23 #endif
24 
25 _LIBCPP_BEGIN_NAMESPACE_STD
26 
27 // GCC is disabled due to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106611
28 #if __has_builtin(__is_nothrow_constructible) && !defined(_LIBCPP_COMPILER_GCC)
29 
30 template < class _Tp, class... _Args>
31 struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible
32     : public integral_constant<bool, __is_nothrow_constructible(_Tp, _Args...)> {};
33 #else
34 
35 template <bool, bool, class _Tp, class... _Args>
36 struct __libcpp_is_nothrow_constructible;
37 
38 template <class _Tp, class... _Args>
39 struct __libcpp_is_nothrow_constructible</*is constructible*/ true, /*is reference*/ false, _Tp, _Args...>
40     : public integral_constant<bool, noexcept(_Tp(std::declval<_Args>()...))> {};
41 
42 template <class _Tp>
43 void __implicit_conversion_to(_Tp) noexcept {}
44 
45 template <class _Tp, class _Arg>
46 struct __libcpp_is_nothrow_constructible</*is constructible*/ true, /*is reference*/ true, _Tp, _Arg>
47     : public integral_constant<bool, noexcept(std::__implicit_conversion_to<_Tp>(std::declval<_Arg>()))> {};
48 
49 template <class _Tp, bool _IsReference, class... _Args>
50 struct __libcpp_is_nothrow_constructible</*is constructible*/ false, _IsReference, _Tp, _Args...> : public false_type {
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,
56                                         is_reference<_Tp>::value,
57                                         _Tp,
58                                         _Args...> {};
59 
60 template <class _Tp, size_t _Ns>
61 struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible<_Tp[_Ns]>
62     : __libcpp_is_nothrow_constructible<is_constructible<_Tp>::value, is_reference<_Tp>::value, _Tp> {};
63 
64 #endif // __has_builtin(__is_nothrow_constructible)
65 
66 #if _LIBCPP_STD_VER >= 17
67 template <class _Tp, class... _Args>
68 inline constexpr bool is_nothrow_constructible_v = is_nothrow_constructible<_Tp, _Args...>::value;
69 #endif
70 
71 // TODO: remove this implementation once https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106611 is fixed
72 #ifdef _LIBCPP_COMPILER_GCC
73 
74 template <class _Tp>
75 struct _LIBCPP_TEMPLATE_VIS is_nothrow_copy_constructible
76     : public is_nothrow_constructible<_Tp, __add_lvalue_reference_t<const _Tp> > {};
77 
78 #else // _LIBCPP_COMPILER_GCC
79 
80 template <class _Tp>
81 struct _LIBCPP_TEMPLATE_VIS is_nothrow_copy_constructible
82     : public integral_constant< bool, __is_nothrow_constructible(_Tp, __add_lvalue_reference_t<const _Tp>)> {};
83 
84 #endif // _LIBCPP_COMPILER_GCC
85 
86 #if _LIBCPP_STD_VER >= 17
87 template <class _Tp>
88 inline constexpr bool is_nothrow_copy_constructible_v = is_nothrow_copy_constructible<_Tp>::value;
89 #endif
90 
91 // TODO: remove this implementation once https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106611 is fixed
92 #ifndef _LIBCPP_COMPILER_GCC
93 
94 template <class _Tp>
95 struct _LIBCPP_TEMPLATE_VIS is_nothrow_move_constructible
96     : public integral_constant<bool, __is_nothrow_constructible(_Tp, __add_rvalue_reference_t<_Tp>)> {};
97 
98 #else // _LIBCPP_COMPILER_GCC
99 
100 template <class _Tp>
101 struct _LIBCPP_TEMPLATE_VIS is_nothrow_move_constructible
102     : public is_nothrow_constructible<_Tp, __add_rvalue_reference_t<_Tp> > {};
103 
104 #endif // _LIBCPP_COMPILER_GCC
105 
106 #if _LIBCPP_STD_VER >= 17
107 template <class _Tp>
108 inline constexpr bool is_nothrow_move_constructible_v = is_nothrow_move_constructible<_Tp>::value;
109 #endif
110 
111 template <class _Tp>
112 struct _LIBCPP_TEMPLATE_VIS is_nothrow_default_constructible
113     : public integral_constant<bool, __is_nothrow_constructible(_Tp)> {};
114 
115 #if _LIBCPP_STD_VER >= 17
116 template <class _Tp>
117 inline constexpr bool is_nothrow_default_constructible_v = __is_nothrow_constructible(_Tp);
118 #endif
119 
120 _LIBCPP_END_NAMESPACE_STD
121 
122 #endif // _LIBCPP___TYPE_TRAITS_IS_NOTHROW_CONSTRUCTIBLE_H
123