1// Allocator traits -*- C++ -*-
2
3// Copyright (C) 2011-2015 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
41namespace __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 : std::false_type { };
48
49 template<typename _Tp>
50 struct __allocator_always_compares_equal<std::allocator<_Tp>>
51 : std::true_type { };
52
53 template<typename, typename> struct array_allocator;
54
55 template<typename _Tp, typename _Array>
56 struct __allocator_always_compares_equal<array_allocator<_Tp, _Array>>
57 : std::true_type { };
58
59 template<typename> struct bitmap_allocator;
60
61 template<typename _Tp>
62 struct __allocator_always_compares_equal<bitmap_allocator<_Tp>>
63 : std::true_type { };
64
65 template<typename> struct malloc_allocator;
66
67 template<typename _Tp>
68 struct __allocator_always_compares_equal<malloc_allocator<_Tp>>
69 : std::true_type { };
70
71 template<typename> struct mt_allocator;
72
73 template<typename _Tp>
74 struct __allocator_always_compares_equal<mt_allocator<_Tp>>
75 : std::true_type { };
76
77 template<typename> struct new_allocator;
78
79 template<typename _Tp>
80 struct __allocator_always_compares_equal<new_allocator<_Tp>>
81 : std::true_type { };
82
83 template<typename> struct pool_allocator;
84
85 template<typename _Tp>
86 struct __allocator_always_compares_equal<pool_allocator<_Tp>>
87 : std::true_type { };
88#endif
89
90/**
91 * @brief Uniform interface to C++98 and C++0x allocators.
92 * @ingroup allocators
93*/
94template<typename _Alloc>
95 struct __alloc_traits
96#if __cplusplus >= 201103L
97 : std::allocator_traits<_Alloc>
98#endif
99 {
100 typedef _Alloc allocator_type;
101#if __cplusplus >= 201103L
102 typedef std::allocator_traits<_Alloc> _Base_type;
103 typedef typename _Base_type::value_type value_type;
104 typedef typename _Base_type::pointer pointer;
105 typedef typename _Base_type::const_pointer const_pointer;
106 typedef typename _Base_type::size_type size_type;
107 typedef typename _Base_type::difference_type difference_type;
108 // C++11 allocators do not define reference or const_reference
109 typedef value_type& reference;
110 typedef const value_type& const_reference;
111 using _Base_type::allocate;
112 using _Base_type::deallocate;
113 using _Base_type::construct;
114 using _Base_type::destroy;
115 using _Base_type::max_size;
116
117 private:
118 template<typename _Ptr>
119 using __is_custom_pointer
120 = std::__and_<std::is_same<pointer, _Ptr>,
121 std::__not_<std::is_pointer<_Ptr>>>;
122
123 public:
124 // overload construct for non-standard pointer types
125 template<typename _Ptr, typename... _Args>
126 static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type
127 construct(_Alloc& __a, _Ptr __p, _Args&&... __args)
128 {
129 _Base_type::construct(__a, std::addressof(*__p),
130 std::forward<_Args>(__args)...);
131 }
132
133 // overload destroy for non-standard pointer types
134 template<typename _Ptr>
135 static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type
136 destroy(_Alloc& __a, _Ptr __p)
137 { _Base_type::destroy(__a, std::addressof(*__p)); }
138
139 static _Alloc _S_select_on_copy(const _Alloc& __a)
140 { return _Base_type::select_on_container_copy_construction(__a); }
141
142 static void _S_on_swap(_Alloc& __a, _Alloc& __b)
143 { std::__alloc_on_swap(__a, __b); }
144
145 static constexpr bool _S_propagate_on_copy_assign()
146 { return _Base_type::propagate_on_container_copy_assignment::value; }
147
148 static constexpr bool _S_propagate_on_move_assign()
149 { return _Base_type::propagate_on_container_move_assignment::value; }
150
151 static constexpr bool _S_propagate_on_swap()
152 { return _Base_type::propagate_on_container_swap::value; }
153
154 static constexpr bool _S_always_equal()
155 { return __allocator_always_compares_equal<_Alloc>::value; }
156
157 static constexpr bool _S_nothrow_move()
158 { return _S_propagate_on_move_assign() || _S_always_equal(); }
159
160 static constexpr bool _S_nothrow_swap()
161 {
162 using std::swap;
163 return !_S_propagate_on_swap()
164 || noexcept(swap(std::declval<_Alloc&>(), std::declval<_Alloc&>()));
165 }
166
167 template<typename _Tp>
168 struct rebind
169 { typedef typename _Base_type::template rebind_alloc<_Tp> other; };
170#else
171
172 typedef typename _Alloc::pointer pointer;
173 typedef typename _Alloc::const_pointer const_pointer;
174 typedef typename _Alloc::value_type value_type;
175 typedef typename _Alloc::reference reference;
176 typedef typename _Alloc::const_reference const_reference;
177 typedef typename _Alloc::size_type size_type;
178 typedef typename _Alloc::difference_type difference_type;
179
180 static pointer
181 allocate(_Alloc& __a, size_type __n)
182 { return __a.allocate(__n); }
183
184 static void deallocate(_Alloc& __a, pointer __p, size_type __n)
185 { __a.deallocate(__p, __n); }
186
187 template<typename _Tp>
188 static void construct(_Alloc& __a, pointer __p, const _Tp& __arg)
189 { __a.construct(__p, __arg); }
190
191 static void destroy(_Alloc& __a, pointer __p)
192 { __a.destroy(__p); }
193
194 static size_type max_size(const _Alloc& __a)
195 { return __a.max_size(); }
196
197 static const _Alloc& _S_select_on_copy(const _Alloc& __a) { return __a; }
198
199 static void _S_on_swap(_Alloc& __a, _Alloc& __b)
200 {
201 // _GLIBCXX_RESOLVE_LIB_DEFECTS
202 // 431. Swapping containers with unequal allocators.
203 std::__alloc_swap<_Alloc>::_S_do_it(__a, __b);
204 }
205
206 template<typename _Tp>
207 struct rebind
208 { typedef typename _Alloc::template rebind<_Tp>::other other; };
209#endif
210 };
211
212_GLIBCXX_END_NAMESPACE_VERSION
213} // namespace __gnu_cxx
214
215#endif
216