1 // Allocator traits -*- C++ -*-
3 // Copyright (C) 2011, 2012 Free Software Foundation, Inc.
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)
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.
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.
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/>.
25 /** @file ext/alloc_traits.h
26 * This file is a GNU extension to the Standard C++ Library.
29 #ifndef _EXT_ALLOC_TRAITS_H
30 #define _EXT_ALLOC_TRAITS_H 1
32 #pragma GCC system_header
34 #ifdef __GXX_EXPERIMENTAL_CXX0X__
35 # include <bits/move.h>
36 # include <bits/alloc_traits.h>
38 # include <bits/allocator.h> // for __alloc_swap
41 namespace std _GLIBCXX_VISIBILITY(default)
43 _GLIBCXX_BEGIN_NAMESPACE_VERSION
44 template<typename> struct allocator;
45 _GLIBCXX_END_NAMESPACE_VERSION
48 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
50 _GLIBCXX_BEGIN_NAMESPACE_VERSION
52 #ifdef __GXX_EXPERIMENTAL_CXX0X__
53 template<typename _Alloc>
54 struct __allocator_always_compares_equal
55 { static const bool value = false; };
57 template<typename _Alloc>
58 const bool __allocator_always_compares_equal<_Alloc>::value;
60 template<typename _Tp>
61 struct __allocator_always_compares_equal<std::allocator<_Tp>>
62 { static const bool value = true; };
64 template<typename _Tp>
65 const bool __allocator_always_compares_equal<std::allocator<_Tp>>::value;
67 template<typename, typename> struct array_allocator;
69 template<typename _Tp, typename _Array>
70 struct __allocator_always_compares_equal<array_allocator<_Tp, _Array>>
71 { static const bool value = true; };
73 template<typename _Tp, typename _Array>
75 __allocator_always_compares_equal<array_allocator<_Tp, _Array>>::value;
77 template<typename> struct mt_allocator;
79 template<typename _Tp>
80 struct __allocator_always_compares_equal<mt_allocator<_Tp>>
81 { static const bool value = true; };
83 template<typename _Tp>
84 const bool __allocator_always_compares_equal<mt_allocator<_Tp>>::value;
86 template<typename> struct new_allocator;
88 template<typename _Tp>
89 struct __allocator_always_compares_equal<new_allocator<_Tp>>
90 { static const bool value = true; };
92 template<typename _Tp>
93 const bool __allocator_always_compares_equal<new_allocator<_Tp>>::value;
95 template<typename> struct pool_allocator;
97 template<typename _Tp>
98 struct __allocator_always_compares_equal<pool_allocator<_Tp>>
99 { static const bool value = true; };
101 template<typename _Tp>
102 const bool __allocator_always_compares_equal<pool_allocator<_Tp>>::value;
106 * @brief Uniform interface to C++98 and C++0x allocators.
107 * @ingroup allocators
109 template<typename _Alloc>
110 struct __alloc_traits
111 #ifdef __GXX_EXPERIMENTAL_CXX0X__
112 : std::allocator_traits<_Alloc>
115 typedef _Alloc allocator_type;
116 #ifdef __GXX_EXPERIMENTAL_CXX0X__
117 typedef std::allocator_traits<_Alloc> _Base_type;
118 typedef typename _Base_type::value_type value_type;
119 typedef typename _Base_type::pointer pointer;
120 typedef typename _Base_type::const_pointer const_pointer;
121 typedef typename _Base_type::size_type size_type;
122 // C++0x allocators do not define reference or const_reference
123 typedef value_type& reference;
124 typedef const value_type& const_reference;
125 using _Base_type::allocate;
126 using _Base_type::deallocate;
127 using _Base_type::construct;
128 using _Base_type::destroy;
129 using _Base_type::max_size;
132 template<typename _Ptr>
133 struct __is_custom_pointer
134 : std::integral_constant<bool, std::is_same<pointer, _Ptr>::value
135 && !std::is_pointer<_Ptr>::value>
139 // overload construct for non-standard pointer types
140 template<typename _Ptr, typename... _Args>
141 static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type
142 construct(_Alloc& __a, _Ptr __p, _Args&&... __args)
144 _Base_type::construct(__a, std::addressof(*__p),
145 std::forward<_Args>(__args)...);
148 // overload destroy for non-standard pointer types
149 template<typename _Ptr>
150 static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type
151 destroy(_Alloc& __a, _Ptr __p)
152 { _Base_type::destroy(__a, std::addressof(*__p)); }
154 static _Alloc _S_select_on_copy(const _Alloc& __a)
155 { return _Base_type::select_on_container_copy_construction(__a); }
157 static void _S_on_swap(_Alloc& __a, _Alloc& __b)
158 { std::__alloc_on_swap(__a, __b); }
160 static constexpr bool _S_propagate_on_copy_assign()
161 { return _Base_type::propagate_on_container_copy_assignment::value; }
163 static constexpr bool _S_propagate_on_move_assign()
164 { return _Base_type::propagate_on_container_move_assignment::value; }
166 static constexpr bool _S_propagate_on_swap()
167 { return _Base_type::propagate_on_container_swap::value; }
169 static constexpr bool _S_always_equal()
170 { return __allocator_always_compares_equal<_Alloc>::value; }
172 static constexpr bool _S_nothrow_move()
173 { return _S_propagate_on_move_assign() || _S_always_equal(); }
175 static constexpr bool _S_nothrow_swap()
178 return !_S_propagate_on_swap()
179 || noexcept(swap(std::declval<_Alloc&>(), std::declval<_Alloc&>()));
182 template<typename _Tp>
184 { typedef typename _Base_type::template rebind_alloc<_Tp> other; };
187 typedef typename _Alloc::pointer pointer;
188 typedef typename _Alloc::const_pointer const_pointer;
189 typedef typename _Alloc::value_type value_type;
190 typedef typename _Alloc::reference reference;
191 typedef typename _Alloc::const_reference const_reference;
192 typedef typename _Alloc::size_type size_type;
195 allocate(_Alloc& __a, size_type __n)
196 { return __a.allocate(__n); }
198 static void deallocate(_Alloc& __a, pointer __p, size_type __n)
199 { __a.deallocate(__p, __n); }
201 template<typename _Tp>
202 static void construct(_Alloc& __a, pointer __p, const _Tp& __arg)
203 { __a.construct(__p, __arg); }
205 static void destroy(_Alloc& __a, pointer __p)
206 { __a.destroy(__p); }
208 static size_type max_size(const _Alloc& __a)
209 { return __a.max_size(); }
211 static const _Alloc& _S_select_on_copy(const _Alloc& __a) { return __a; }
213 static void _S_on_swap(_Alloc& __a, _Alloc& __b)
215 // _GLIBCXX_RESOLVE_LIB_DEFECTS
216 // 431. Swapping containers with unequal allocators.
217 std::__alloc_swap<_Alloc>::_S_do_it(__a, __b);
220 template<typename _Tp>
222 { typedef typename _Alloc::template rebind<_Tp>::other other; };
226 _GLIBCXX_END_NAMESPACE_VERSION