1 // Allocator traits -*- C++ -*- 2 3 // Copyright (C) 2011, 2012 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 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 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 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 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 mt_allocator; 78 79 template<typename _Tp> 80 struct __allocator_always_compares_equal<mt_allocator<_Tp>> 81 { static const bool value = true; }; 82 83 template<typename _Tp> 84 const bool __allocator_always_compares_equal<mt_allocator<_Tp>>::value; 85 86 template<typename> struct new_allocator; 87 88 template<typename _Tp> 89 struct __allocator_always_compares_equal<new_allocator<_Tp>> 90 { static const bool value = true; }; 91 92 template<typename _Tp> 93 const bool __allocator_always_compares_equal<new_allocator<_Tp>>::value; 94 95 template<typename> struct pool_allocator; 96 97 template<typename _Tp> 98 struct __allocator_always_compares_equal<pool_allocator<_Tp>> 99 { static const bool value = true; }; 100 101 template<typename _Tp> 102 const bool __allocator_always_compares_equal<pool_allocator<_Tp>>::value; 103 #endif 104 105 /** 106 * @brief Uniform interface to C++98 and C++0x allocators. 107 * @ingroup allocators 108 */ 109 template<typename _Alloc> 110 struct __alloc_traits 111 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 112 : std::allocator_traits<_Alloc> 113 #endif 114 { 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; 130 131 private: 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> 136 { }; 137 138 public: 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) 143 { 144 _Base_type::construct(__a, std::addressof(*__p), 145 std::forward<_Args>(__args)...); 146 } 147 148 // 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)); } 153 154 static _Alloc _S_select_on_copy(const _Alloc& __a) 155 { return _Base_type::select_on_container_copy_construction(__a); } 156 157 static void _S_on_swap(_Alloc& __a, _Alloc& __b) 158 { std::__alloc_on_swap(__a, __b); } 159 160 static constexpr bool _S_propagate_on_copy_assign() 161 { return _Base_type::propagate_on_container_copy_assignment::value; } 162 163 static constexpr bool _S_propagate_on_move_assign() 164 { return _Base_type::propagate_on_container_move_assignment::value; } 165 166 static constexpr bool _S_propagate_on_swap() 167 { return _Base_type::propagate_on_container_swap::value; } 168 169 static constexpr bool _S_always_equal() 170 { return __allocator_always_compares_equal<_Alloc>::value; } 171 172 static constexpr bool _S_nothrow_move() 173 { return _S_propagate_on_move_assign() || _S_always_equal(); } 174 175 static constexpr bool _S_nothrow_swap() 176 { 177 using std::swap; 178 return !_S_propagate_on_swap() 179 || noexcept(swap(std::declval<_Alloc&>(), std::declval<_Alloc&>())); 180 } 181 182 template<typename _Tp> 183 struct rebind 184 { typedef typename _Base_type::template rebind_alloc<_Tp> other; }; 185 #else 186 187 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; 193 194 static pointer 195 allocate(_Alloc& __a, size_type __n) 196 { return __a.allocate(__n); } 197 198 static void deallocate(_Alloc& __a, pointer __p, size_type __n) 199 { __a.deallocate(__p, __n); } 200 201 template<typename _Tp> 202 static void construct(_Alloc& __a, pointer __p, const _Tp& __arg) 203 { __a.construct(__p, __arg); } 204 205 static void destroy(_Alloc& __a, pointer __p) 206 { __a.destroy(__p); } 207 208 static size_type max_size(const _Alloc& __a) 209 { return __a.max_size(); } 210 211 static const _Alloc& _S_select_on_copy(const _Alloc& __a) { return __a; } 212 213 static void _S_on_swap(_Alloc& __a, _Alloc& __b) 214 { 215 // _GLIBCXX_RESOLVE_LIB_DEFECTS 216 // 431. Swapping containers with unequal allocators. 217 std::__alloc_swap<_Alloc>::_S_do_it(__a, __b); 218 } 219 220 template<typename _Tp> 221 struct rebind 222 { typedef typename _Alloc::template rebind<_Tp>::other other; }; 223 #endif 224 }; 225 226 _GLIBCXX_END_NAMESPACE_VERSION 227 } // namespace 228 229 #endif 230