libstdc++

ext/alloc_traits.h
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1 // Allocator traits -*- C++ -*-
2
3 // Copyright (C) 2011-2013 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 /** @file ext/alloc_traits.h
26 * This file is a GNU extension to the Standard C++ Library.
27 */
28
29 #ifndef _EXT_ALLOC_TRAITS_H
30 #define _EXT_ALLOC_TRAITS_H 1
31
32 #pragma GCC system_header
33
34 #if __cplusplus >= 201103L
35 # include <bits/move.h>
36 # include <bits/alloc_traits.h>
37 #else
38 # include <bits/allocator.h> // for __alloc_swap
39 #endif
40
41 namespace std _GLIBCXX_VISIBILITY(default)
42 {
43 _GLIBCXX_BEGIN_NAMESPACE_VERSION
44 template<typename> struct allocator;
45 _GLIBCXX_END_NAMESPACE_VERSION
46 } // namespace
47
48 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
49 {
50 _GLIBCXX_BEGIN_NAMESPACE_VERSION
51
52 #if __cplusplus >= 201103L
53 template<typename _Alloc>
54 struct __allocator_always_compares_equal
55 { static const bool value = false; };
56
57 template<typename _Alloc>
58 const bool __allocator_always_compares_equal<_Alloc>::value;
59
60 template<typename _Tp>
61 struct __allocator_always_compares_equal<std::allocator<_Tp>>
62 { static const bool value = true; };
63
64 template<typename _Tp>
65 const bool __allocator_always_compares_equal<std::allocator<_Tp>>::value;
66
67 template<typename, typename> struct array_allocator;
68
69 template<typename _Tp, typename _Array>
70 struct __allocator_always_compares_equal<array_allocator<_Tp, _Array>>
71 { static const bool value = true; };
72
73 template<typename _Tp, typename _Array>
74 const bool
75 __allocator_always_compares_equal<array_allocator<_Tp, _Array>>::value;
76
77 template<typename> struct bitmap_allocator;
78
79 template<typename _Tp>
80 struct __allocator_always_compares_equal<bitmap_allocator<_Tp>>
81 { static const bool value = true; };
82
83 template<typename _Tp>
84 const bool __allocator_always_compares_equal<bitmap_allocator<_Tp>>::value;
85
86 template<typename> struct malloc_allocator;
87
88 template<typename _Tp>
89 struct __allocator_always_compares_equal<malloc_allocator<_Tp>>
90 { static const bool value = true; };
91
92 template<typename _Tp>
93 const bool __allocator_always_compares_equal<malloc_allocator<_Tp>>::value;
94
95 template<typename> struct mt_allocator;
96
97 template<typename _Tp>
98 struct __allocator_always_compares_equal<mt_allocator<_Tp>>
99 { static const bool value = true; };
100
101 template<typename _Tp>
102 const bool __allocator_always_compares_equal<mt_allocator<_Tp>>::value;
103
104 template<typename> struct new_allocator;
105
106 template<typename _Tp>
107 struct __allocator_always_compares_equal<new_allocator<_Tp>>
108 { static const bool value = true; };
109
110 template<typename _Tp>
111 const bool __allocator_always_compares_equal<new_allocator<_Tp>>::value;
112
113 template<typename> struct pool_allocator;
114
115 template<typename _Tp>
116 struct __allocator_always_compares_equal<pool_allocator<_Tp>>
117 { static const bool value = true; };
118
119 template<typename _Tp>
120 const bool __allocator_always_compares_equal<pool_allocator<_Tp>>::value;
121 #endif
122
123 /**
124 * @brief Uniform interface to C++98 and C++0x allocators.
125 * @ingroup allocators
126 */
127 template<typename _Alloc>
128 struct __alloc_traits
129 #if __cplusplus >= 201103L
130 : std::allocator_traits<_Alloc>
131 #endif
132 {
133 typedef _Alloc allocator_type;
134 #if __cplusplus >= 201103L
135 typedef std::allocator_traits<_Alloc> _Base_type;
136 typedef typename _Base_type::value_type value_type;
137 typedef typename _Base_type::pointer pointer;
138 typedef typename _Base_type::const_pointer const_pointer;
139 typedef typename _Base_type::size_type size_type;
140 typedef typename _Base_type::difference_type difference_type;
141 // C++0x allocators do not define reference or const_reference
142 typedef value_type& reference;
143 typedef const value_type& const_reference;
144 using _Base_type::allocate;
145 using _Base_type::deallocate;
146 using _Base_type::construct;
147 using _Base_type::destroy;
148 using _Base_type::max_size;
149
150 private:
151 template<typename _Ptr>
152 struct __is_custom_pointer
153 : std::integral_constant<bool, std::is_same<pointer, _Ptr>::value
154 && !std::is_pointer<_Ptr>::value>
155 { };
156
157 public:
158 // overload construct for non-standard pointer types
159 template<typename _Ptr, typename... _Args>
160 static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type
161 construct(_Alloc& __a, _Ptr __p, _Args&&... __args)
162 {
163 _Base_type::construct(__a, std::addressof(*__p),
164 std::forward<_Args>(__args)...);
165 }
166
167 // overload destroy for non-standard pointer types
168 template<typename _Ptr>
169 static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type
170 destroy(_Alloc& __a, _Ptr __p)
171 { _Base_type::destroy(__a, std::addressof(*__p)); }
172
173 static _Alloc _S_select_on_copy(const _Alloc& __a)
174 { return _Base_type::select_on_container_copy_construction(__a); }
175
176 static void _S_on_swap(_Alloc& __a, _Alloc& __b)
177 { std::__alloc_on_swap(__a, __b); }
178
179 static constexpr bool _S_propagate_on_copy_assign()
180 { return _Base_type::propagate_on_container_copy_assignment::value; }
181
182 static constexpr bool _S_propagate_on_move_assign()
183 { return _Base_type::propagate_on_container_move_assignment::value; }
184
185 static constexpr bool _S_propagate_on_swap()
186 { return _Base_type::propagate_on_container_swap::value; }
187
188 static constexpr bool _S_always_equal()
189 { return __allocator_always_compares_equal<_Alloc>::value; }
190
191 static constexpr bool _S_nothrow_move()
192 { return _S_propagate_on_move_assign() || _S_always_equal(); }
193
194 static constexpr bool _S_nothrow_swap()
195 {
196 using std::swap;
197 return !_S_propagate_on_swap()
198 || noexcept(swap(std::declval<_Alloc&>(), std::declval<_Alloc&>()));
199 }
200
201 template<typename _Tp>
202 struct rebind
203 { typedef typename _Base_type::template rebind_alloc<_Tp> other; };
204 #else
205
206 typedef typename _Alloc::pointer pointer;
207 typedef typename _Alloc::const_pointer const_pointer;
208 typedef typename _Alloc::value_type value_type;
209 typedef typename _Alloc::reference reference;
210 typedef typename _Alloc::const_reference const_reference;
211 typedef typename _Alloc::size_type size_type;
212 typedef typename _Alloc::difference_type difference_type;
213
214 static pointer
215 allocate(_Alloc& __a, size_type __n)
216 { return __a.allocate(__n); }
217
218 static void deallocate(_Alloc& __a, pointer __p, size_type __n)
219 { __a.deallocate(__p, __n); }
220
221 template<typename _Tp>
222 static void construct(_Alloc& __a, pointer __p, const _Tp& __arg)
223 { __a.construct(__p, __arg); }
224
225 static void destroy(_Alloc& __a, pointer __p)
226 { __a.destroy(__p); }
227
228 static size_type max_size(const _Alloc& __a)
229 { return __a.max_size(); }
230
231 static const _Alloc& _S_select_on_copy(const _Alloc& __a) { return __a; }
232
233 static void _S_on_swap(_Alloc& __a, _Alloc& __b)
234 {
235 // _GLIBCXX_RESOLVE_LIB_DEFECTS
236 // 431. Swapping containers with unequal allocators.
237 std::__alloc_swap<_Alloc>::_S_do_it(__a, __b);
238 }
239
240 template<typename _Tp>
241 struct rebind
242 { typedef typename _Alloc::template rebind<_Tp>::other other; };
243 #endif
244 };
245
246 _GLIBCXX_END_NAMESPACE_VERSION
247 } // namespace
248
249 #endif