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/alloc_traits.h> 36 #else 37 # include <bits/allocator.h> // for __alloc_swap 38 #endif 39 40 namespace std _GLIBCXX_VISIBILITY(default) 41 { 42 _GLIBCXX_BEGIN_NAMESPACE_VERSION 43 template<typename> struct allocator; 44 _GLIBCXX_END_NAMESPACE_VERSION 45 } // namespace 46 47 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) 48 { 49 _GLIBCXX_BEGIN_NAMESPACE_VERSION 50 51 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 52 template<typename _Alloc> 53 struct __allocator_always_compares_equal 54 { static const bool value = false; }; 55 56 template<typename _Alloc> 57 const bool __allocator_always_compares_equal<_Alloc>::value; 58 59 template<typename _Tp> 60 struct __allocator_always_compares_equal<std::allocator<_Tp>> 61 { static const bool value = true; }; 62 63 template<typename _Tp> 64 const bool __allocator_always_compares_equal<std::allocator<_Tp>>::value; 65 66 template<typename, typename> struct array_allocator; 67 68 template<typename _Tp, typename _Array> 69 struct __allocator_always_compares_equal<array_allocator<_Tp, _Array>> 70 { static const bool value = true; }; 71 72 template<typename _Tp, typename _Array> 73 const bool 74 __allocator_always_compares_equal<array_allocator<_Tp, _Array>>::value; 75 76 template<typename> struct mt_allocator; 77 78 template<typename _Tp> 79 struct __allocator_always_compares_equal<mt_allocator<_Tp>> 80 { static const bool value = true; }; 81 82 template<typename _Tp> 83 const bool __allocator_always_compares_equal<mt_allocator<_Tp>>::value; 84 85 template<typename> struct new_allocator; 86 87 template<typename _Tp> 88 struct __allocator_always_compares_equal<new_allocator<_Tp>> 89 { static const bool value = true; }; 90 91 template<typename _Tp> 92 const bool __allocator_always_compares_equal<new_allocator<_Tp>>::value; 93 94 template<typename> struct pool_allocator; 95 96 template<typename _Tp> 97 struct __allocator_always_compares_equal<pool_allocator<_Tp>> 98 { static const bool value = true; }; 99 100 template<typename _Tp> 101 const bool __allocator_always_compares_equal<pool_allocator<_Tp>>::value; 102 #endif 103 104 /** 105 * @brief Uniform interface to C++98 and C++0x allocators. 106 * @ingroup allocators 107 */ 108 template<typename _Alloc> 109 struct __alloc_traits 110 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 111 : std::allocator_traits<_Alloc> 112 #endif 113 { 114 typedef _Alloc allocator_type; 115 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 116 typedef std::allocator_traits<_Alloc> _Base_type; 117 typedef typename _Base_type::value_type value_type; 118 typedef typename _Base_type::pointer pointer; 119 typedef typename _Base_type::const_pointer const_pointer; 120 typedef typename _Base_type::size_type size_type; 121 // C++0x allocators do not define reference or const_reference 122 typedef value_type& reference; 123 typedef const value_type& const_reference; 124 using _Base_type::allocate; 125 using _Base_type::deallocate; 126 using _Base_type::construct; 127 using _Base_type::destroy; 128 using _Base_type::max_size; 129 130 private: 131 template<typename _Ptr> 132 struct __is_custom_pointer 133 : std::integral_constant<bool, std::is_same<pointer, _Ptr>::value 134 && !std::is_pointer<_Ptr>::value> 135 { }; 136 137 public: 138 // overload construct for non-standard pointer types 139 template<typename _Ptr, typename... _Args> 140 static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type 141 construct(_Alloc& __a, _Ptr __p, _Args&&... __args) 142 { 143 _Base_type::construct(__a, std::addressof(*__p), 144 std::forward<_Args>(__args)...); 145 } 146 147 // overload destroy for non-standard pointer types 148 template<typename _Ptr> 149 static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type 150 destroy(_Alloc& __a, _Ptr __p) 151 { _Base_type::destroy(__a, std::addressof(*__p)); } 152 153 static _Alloc _S_select_on_copy(const _Alloc& __a) 154 { return _Base_type::select_on_container_copy_construction(__a); } 155 156 static void _S_on_swap(_Alloc& __a, _Alloc& __b) 157 { std::__alloc_on_swap(__a, __b); } 158 159 static constexpr bool _S_propagate_on_copy_assign() 160 { return _Base_type::propagate_on_container_copy_assignment::value; } 161 162 static constexpr bool _S_propagate_on_move_assign() 163 { return _Base_type::propagate_on_container_move_assignment::value; } 164 165 static constexpr bool _S_propagate_on_swap() 166 { return _Base_type::propagate_on_container_swap::value; } 167 168 static constexpr bool _S_always_equal() 169 { return __allocator_always_compares_equal<_Alloc>::value; } 170 171 static constexpr bool _S_nothrow_move() 172 { return _S_propagate_on_move_assign() || _S_always_equal(); } 173 174 static constexpr bool _S_nothrow_swap() 175 { 176 using std::swap; 177 return !_S_propagate_on_swap() 178 || noexcept(swap(std::declval<_Alloc&>(), std::declval<_Alloc&>())); 179 } 180 181 template<typename _Tp> 182 struct rebind 183 { typedef typename _Base_type::template rebind_alloc<_Tp> other; }; 184 #else 185 186 typedef typename _Alloc::pointer pointer; 187 typedef typename _Alloc::const_pointer const_pointer; 188 typedef typename _Alloc::value_type value_type; 189 typedef typename _Alloc::reference reference; 190 typedef typename _Alloc::const_reference const_reference; 191 typedef typename _Alloc::size_type size_type; 192 193 static pointer 194 allocate(_Alloc& __a, size_type __n) 195 { return __a.allocate(__n); } 196 197 static void deallocate(_Alloc& __a, pointer __p, size_type __n) 198 { __a.deallocate(__p, __n); } 199 200 template<typename _Tp> 201 static void construct(_Alloc& __a, pointer __p, const _Tp& __arg) 202 { __a.construct(__p, __arg); } 203 204 static void destroy(_Alloc& __a, pointer __p) 205 { __a.destroy(__p); } 206 207 static size_type max_size(const _Alloc& __a) 208 { return __a.max_size(); } 209 210 static const _Alloc& _S_select_on_copy(const _Alloc& __a) { return __a; } 211 212 static void _S_on_swap(_Alloc& __a, _Alloc& __b) 213 { 214 // _GLIBCXX_RESOLVE_LIB_DEFECTS 215 // 431. Swapping containers with unequal allocators. 216 std::__alloc_swap<_Alloc>::_S_do_it(__a, __b); 217 } 218 219 template<typename _Tp> 220 struct rebind 221 { typedef typename _Alloc::template rebind<_Tp>::other other; }; 222 #endif 223 }; 224 225 _GLIBCXX_END_NAMESPACE_VERSION 226 } // namespace 227 228 #endif 229
