1 | // Uses-allocator Construction -*- C++ -*- |
2 | |
3 | // Copyright (C) 2010-2017 Free Software Foundation, Inc. |
4 | // |
5 | // This file is part of the GNU ISO C++ Library. This library is free |
6 | // software; you can redistribute it and/or modify it under the |
7 | // terms of the GNU General Public License as published by the |
8 | // Free Software Foundation; either version 3, or (at your option) |
9 | // any later version. |
10 | |
11 | // This library is distributed in the hope that it will be useful, |
12 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14 | // GNU General Public License for more details. |
15 | |
16 | // Under Section 7 of GPL version 3, you are granted additional |
17 | // permissions described in the GCC Runtime Library Exception, version |
18 | // 3.1, as published by the Free Software Foundation. |
19 | |
20 | // You should have received a copy of the GNU General Public License and |
21 | // a copy of the GCC Runtime Library Exception along with this program; |
22 | // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
23 | // <http://www.gnu.org/licenses/>. |
24 | |
25 | #ifndef _USES_ALLOCATOR_H |
26 | #define _USES_ALLOCATOR_H 1 |
27 | |
28 | #if __cplusplus < 201103L |
29 | # include <bits/c++0x_warning.h> |
30 | #else |
31 | |
32 | #include <type_traits> |
33 | #include <bits/move.h> |
34 | |
35 | namespace std _GLIBCXX_VISIBILITY(default) |
36 | { |
37 | _GLIBCXX_BEGIN_NAMESPACE_VERSION |
38 | |
39 | struct __erased_type { }; |
40 | |
41 | template<typename _Alloc, typename _Tp> |
42 | using __is_erased_or_convertible |
43 | = __or_<is_same<_Tp, __erased_type>, is_convertible<_Alloc, _Tp>>; |
44 | |
45 | /// [allocator.tag] |
46 | struct allocator_arg_t { explicit allocator_arg_t() = default; }; |
47 | |
48 | _GLIBCXX17_INLINE constexpr allocator_arg_t allocator_arg = |
49 | allocator_arg_t(); |
50 | |
51 | template<typename _Tp, typename _Alloc, typename = __void_t<>> |
52 | struct __uses_allocator_helper |
53 | : false_type { }; |
54 | |
55 | template<typename _Tp, typename _Alloc> |
56 | struct __uses_allocator_helper<_Tp, _Alloc, |
57 | __void_t<typename _Tp::allocator_type>> |
58 | : __is_erased_or_convertible<_Alloc, typename _Tp::allocator_type>::type |
59 | { }; |
60 | |
61 | /// [allocator.uses.trait] |
62 | template<typename _Tp, typename _Alloc> |
63 | struct uses_allocator |
64 | : __uses_allocator_helper<_Tp, _Alloc>::type |
65 | { }; |
66 | |
67 | struct __uses_alloc_base { }; |
68 | |
69 | struct __uses_alloc0 : __uses_alloc_base |
70 | { |
71 | struct _Sink { void operator=(const void*) { } } _M_a; |
72 | }; |
73 | |
74 | template<typename _Alloc> |
75 | struct __uses_alloc1 : __uses_alloc_base { const _Alloc* _M_a; }; |
76 | |
77 | template<typename _Alloc> |
78 | struct __uses_alloc2 : __uses_alloc_base { const _Alloc* _M_a; }; |
79 | |
80 | template<bool, typename _Tp, typename _Alloc, typename... _Args> |
81 | struct __uses_alloc; |
82 | |
83 | template<typename _Tp, typename _Alloc, typename... _Args> |
84 | struct __uses_alloc<true, _Tp, _Alloc, _Args...> |
85 | : conditional< |
86 | is_constructible<_Tp, allocator_arg_t, _Alloc, _Args...>::value, |
87 | __uses_alloc1<_Alloc>, |
88 | __uses_alloc2<_Alloc>>::type |
89 | { |
90 | static_assert(__or_< |
91 | is_constructible<_Tp, allocator_arg_t, _Alloc, _Args...>, |
92 | is_constructible<_Tp, _Args..., _Alloc>>::value, "construction with" |
93 | " an allocator must be possible if uses_allocator is true" ); |
94 | }; |
95 | |
96 | template<typename _Tp, typename _Alloc, typename... _Args> |
97 | struct __uses_alloc<false, _Tp, _Alloc, _Args...> |
98 | : __uses_alloc0 { }; |
99 | |
100 | template<typename _Tp, typename _Alloc, typename... _Args> |
101 | using __uses_alloc_t = |
102 | __uses_alloc<uses_allocator<_Tp, _Alloc>::value, _Tp, _Alloc, _Args...>; |
103 | |
104 | template<typename _Tp, typename _Alloc, typename... _Args> |
105 | inline __uses_alloc_t<_Tp, _Alloc, _Args...> |
106 | __use_alloc(const _Alloc& __a) |
107 | { |
108 | __uses_alloc_t<_Tp, _Alloc, _Args...> __ret; |
109 | __ret._M_a = std::__addressof(__a); |
110 | return __ret; |
111 | } |
112 | |
113 | template<typename _Tp, typename _Alloc, typename... _Args> |
114 | void |
115 | __use_alloc(const _Alloc&&) = delete; |
116 | |
117 | #if __cplusplus > 201402L |
118 | template <typename _Tp, typename _Alloc> |
119 | inline constexpr bool uses_allocator_v = |
120 | uses_allocator<_Tp, _Alloc>::value; |
121 | #endif // C++17 |
122 | |
123 | template<template<typename...> class _Predicate, |
124 | typename _Tp, typename _Alloc, typename... _Args> |
125 | struct __is_uses_allocator_predicate |
126 | : conditional<uses_allocator<_Tp, _Alloc>::value, |
127 | __or_<_Predicate<_Tp, allocator_arg_t, _Alloc, _Args...>, |
128 | _Predicate<_Tp, _Args..., _Alloc>>, |
129 | _Predicate<_Tp, _Args...>>::type { }; |
130 | |
131 | template<typename _Tp, typename _Alloc, typename... _Args> |
132 | struct __is_uses_allocator_constructible |
133 | : __is_uses_allocator_predicate<is_constructible, _Tp, _Alloc, _Args...> |
134 | { }; |
135 | |
136 | #if __cplusplus >= 201402L |
137 | template<typename _Tp, typename _Alloc, typename... _Args> |
138 | _GLIBCXX17_INLINE constexpr bool __is_uses_allocator_constructible_v = |
139 | __is_uses_allocator_constructible<_Tp, _Alloc, _Args...>::value; |
140 | #endif // C++14 |
141 | |
142 | template<typename _Tp, typename _Alloc, typename... _Args> |
143 | struct __is_nothrow_uses_allocator_constructible |
144 | : __is_uses_allocator_predicate<is_nothrow_constructible, |
145 | _Tp, _Alloc, _Args...> |
146 | { }; |
147 | |
148 | |
149 | #if __cplusplus >= 201402L |
150 | template<typename _Tp, typename _Alloc, typename... _Args> |
151 | _GLIBCXX17_INLINE constexpr bool |
152 | __is_nothrow_uses_allocator_constructible_v = |
153 | __is_nothrow_uses_allocator_constructible<_Tp, _Alloc, _Args...>::value; |
154 | #endif // C++14 |
155 | |
156 | template<typename _Tp, typename... _Args> |
157 | void __uses_allocator_construct_impl(__uses_alloc0 __a, _Tp* __ptr, |
158 | _Args&&... __args) |
159 | { ::new ((void*)__ptr) _Tp(std::forward<_Args>(__args)...); } |
160 | |
161 | template<typename _Tp, typename _Alloc, typename... _Args> |
162 | void __uses_allocator_construct_impl(__uses_alloc1<_Alloc> __a, _Tp* __ptr, |
163 | _Args&&... __args) |
164 | { |
165 | ::new ((void*)__ptr) _Tp(allocator_arg, *__a._M_a, |
166 | std::forward<_Args>(__args)...); |
167 | } |
168 | |
169 | template<typename _Tp, typename _Alloc, typename... _Args> |
170 | void __uses_allocator_construct_impl(__uses_alloc2<_Alloc> __a, _Tp* __ptr, |
171 | _Args&&... __args) |
172 | { ::new ((void*)__ptr) _Tp(std::forward<_Args>(__args)..., *__a._M_a); } |
173 | |
174 | template<typename _Tp, typename _Alloc, typename... _Args> |
175 | void __uses_allocator_construct(const _Alloc& __a, _Tp* __ptr, |
176 | _Args&&... __args) |
177 | { |
178 | __uses_allocator_construct_impl(__use_alloc<_Tp, _Alloc, _Args...>(__a), |
179 | __ptr, std::forward<_Args>(__args)...); |
180 | } |
181 | |
182 | _GLIBCXX_END_NAMESPACE_VERSION |
183 | } // namespace std |
184 | |
185 | #endif |
186 | #endif |
187 | |