1 // Allocators -*- C++ -*- 2 3 // Copyright (C) 2001-2013 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 /* 26 * Copyright (c) 1996-1997 27 * Silicon Graphics Computer Systems, Inc. 28 * 29 * Permission to use, copy, modify, distribute and sell this software 30 * and its documentation for any purpose is hereby granted without fee, 31 * provided that the above copyright notice appear in all copies and 32 * that both that copyright notice and this permission notice appear 33 * in supporting documentation. Silicon Graphics makes no 34 * representations about the suitability of this software for any 35 * purpose. It is provided "as is" without express or implied warranty. 36 */ 37 38 /** @file bits/allocator.h 39 * This is an internal header file, included by other library headers. 40 * Do not attempt to use it directly. @headername{memory} 41 */ 42 43 #ifndef _ALLOCATOR_H 44 #define _ALLOCATOR_H 1 45 46 #include <bits/c++allocator.h> // Define the base class to std::allocator. 47 #include <bits/memoryfwd.h> 48 #if __cplusplus >= 201103L 49 #include <type_traits> 50 #endif 51 52 namespace std _GLIBCXX_VISIBILITY(default) 53 { 54 _GLIBCXX_BEGIN_NAMESPACE_VERSION 55 56 /** 57 * @addtogroup allocators 58 * @{ 59 */ 60 61 /// allocator<void> specialization. 62 template<> 63 class allocator<void> 64 { 65 public: 66 typedef size_t size_type; 67 typedef ptrdiff_t difference_type; 68 typedef void* pointer; 69 typedef const void* const_pointer; 70 typedef void value_type; 71 72 template<typename _Tp1> 73 struct rebind 74 { typedef allocator<_Tp1> other; }; 75 76 #if __cplusplus >= 201103L 77 // _GLIBCXX_RESOLVE_LIB_DEFECTS 78 // 2103. std::allocator propagate_on_container_move_assignment 79 typedef true_type propagate_on_container_move_assignment; 80 #endif 81 }; 82 83 /** 84 * @brief The @a standard allocator, as per [20.4]. 85 * 86 * See http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt04ch11.html 87 * for further details. 88 * 89 * @tparam _Tp Type of allocated object. 90 */ 91 template<typename _Tp> 92 class allocator: public __allocator_base<_Tp> 93 { 94 public: 95 typedef size_t size_type; 96 typedef ptrdiff_t difference_type; 97 typedef _Tp* pointer; 98 typedef const _Tp* const_pointer; 99 typedef _Tp& reference; 100 typedef const _Tp& const_reference; 101 typedef _Tp value_type; 102 103 template<typename _Tp1> 104 struct rebind 105 { typedef allocator<_Tp1> other; }; 106 107 #if __cplusplus >= 201103L 108 // _GLIBCXX_RESOLVE_LIB_DEFECTS 109 // 2103. std::allocator propagate_on_container_move_assignment 110 typedef true_type propagate_on_container_move_assignment; 111 #endif 112 113 allocator() throw() { } 114 115 allocator(const allocator& __a) throw() 116 : __allocator_base<_Tp>(__a) { } 117 118 template<typename _Tp1> 119 allocator(const allocator<_Tp1>&) throw() { } 120 121 ~allocator() throw() { } 122 123 // Inherit everything else. 124 }; 125 126 template<typename _T1, typename _T2> 127 inline bool 128 operator==(const allocator<_T1>&, const allocator<_T2>&) 129 { return true; } 130 131 template<typename _Tp> 132 inline bool 133 operator==(const allocator<_Tp>&, const allocator<_Tp>&) 134 { return true; } 135 136 template<typename _T1, typename _T2> 137 inline bool 138 operator!=(const allocator<_T1>&, const allocator<_T2>&) 139 { return false; } 140 141 template<typename _Tp> 142 inline bool 143 operator!=(const allocator<_Tp>&, const allocator<_Tp>&) 144 { return false; } 145 146 /// @} group allocator 147 148 // Inhibit implicit instantiations for required instantiations, 149 // which are defined via explicit instantiations elsewhere. 150 #if _GLIBCXX_EXTERN_TEMPLATE 151 extern template class allocator<char>; 152 extern template class allocator<wchar_t>; 153 #endif 154 155 // Undefine. 156 #undef __allocator_base 157 158 // To implement Option 3 of DR 431. 159 template<typename _Alloc, bool = __is_empty(_Alloc)> 160 struct __alloc_swap 161 { static void _S_do_it(_Alloc&, _Alloc&) { } }; 162 163 template<typename _Alloc> 164 struct __alloc_swap<_Alloc, false> 165 { 166 static void 167 _S_do_it(_Alloc& __one, _Alloc& __two) 168 { 169 // Precondition: swappable allocators. 170 if (__one != __two) 171 swap(__one, __two); 172 } 173 }; 174 175 // Optimize for stateless allocators. 176 template<typename _Alloc, bool = __is_empty(_Alloc)> 177 struct __alloc_neq 178 { 179 static bool 180 _S_do_it(const _Alloc&, const _Alloc&) 181 { return false; } 182 }; 183 184 template<typename _Alloc> 185 struct __alloc_neq<_Alloc, false> 186 { 187 static bool 188 _S_do_it(const _Alloc& __one, const _Alloc& __two) 189 { return __one != __two; } 190 }; 191 192 #if __cplusplus >= 201103L 193 template<typename _Tp, bool 194 = __or_<is_copy_constructible<typename _Tp::value_type>, 195 is_nothrow_move_constructible<typename _Tp::value_type>>::value> 196 struct __shrink_to_fit_aux 197 { static bool _S_do_it(_Tp&) { return false; } }; 198 199 template<typename _Tp> 200 struct __shrink_to_fit_aux<_Tp, true> 201 { 202 static bool 203 _S_do_it(_Tp& __c) 204 { 205 __try 206 { 207 _Tp(__make_move_if_noexcept_iterator(__c.begin()), 208 __make_move_if_noexcept_iterator(__c.end()), 209 __c.get_allocator()).swap(__c); 210 return true; 211 } 212 __catch(...) 213 { return false; } 214 } 215 }; 216 #endif 217 218 _GLIBCXX_END_NAMESPACE_VERSION 219 } // namespace std 220 221 #endif 222
