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