1 // Allocators -*- C++ -*- 2 3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 4 // 2011 Free Software Foundation, Inc. 5 // 6 // This file is part of the GNU ISO C++ Library. This library is free 7 // software; you can redistribute it and/or modify it under the 8 // terms of the GNU General Public License as published by the 9 // Free Software Foundation; either version 3, or (at your option) 10 // any later version. 11 12 // This library is distributed in the hope that it will be useful, 13 // but WITHOUT ANY WARRANTY; without even the implied warranty of 14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 // GNU General Public License for more details. 16 17 // Under Section 7 of GPL version 3, you are granted additional 18 // permissions described in the GCC Runtime Library Exception, version 19 // 3.1, as published by the Free Software Foundation. 20 21 // You should have received a copy of the GNU General Public License and 22 // a copy of the GCC Runtime Library Exception along with this program; 23 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24 // <http://www.gnu.org/licenses/>. 25 26 /* 27 * Copyright (c) 1996-1997 28 * Silicon Graphics Computer Systems, Inc. 29 * 30 * Permission to use, copy, modify, distribute and sell this software 31 * and its documentation for any purpose is hereby granted without fee, 32 * provided that the above copyright notice appear in all copies and 33 * that both that copyright notice and this permission notice appear 34 * in supporting documentation. Silicon Graphics makes no 35 * representations about the suitability of this software for any 36 * purpose. It is provided "as is" without express or implied warranty. 37 */ 38 39 /** @file bits/allocator.h 40 * This is an internal header file, included by other library headers. 41 * Do not attempt to use it directly. @headername{memory} 42 */ 43 44 #ifndef _ALLOCATOR_H 45 #define _ALLOCATOR_H 1 46 47 // Define the base class to std::allocator. 48 #include <bits/c++allocator.h> 49 50 namespace std _GLIBCXX_VISIBILITY(default) 51 { 52 _GLIBCXX_BEGIN_NAMESPACE_VERSION 53 54 /** 55 * @defgroup allocators Allocators 56 * @ingroup memory 57 * 58 * Classes encapsulating memory operations. 59 * 60 * @{ 61 */ 62 63 template<typename _Tp> 64 class allocator; 65 66 /// allocator<void> specialization. 67 template<> 68 class allocator<void> 69 { 70 public: 71 typedef size_t size_type; 72 typedef ptrdiff_t difference_type; 73 typedef void* pointer; 74 typedef const void* const_pointer; 75 typedef void value_type; 76 77 template<typename _Tp1> 78 struct rebind 79 { typedef allocator<_Tp1> other; }; 80 }; 81 82 /** 83 * @brief The @a standard allocator, as per [20.4]. 84 * 85 * See http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt04ch11.html 86 * for further details. 87 */ 88 template<typename _Tp> 89 class allocator: public __glibcxx_base_allocator<_Tp> 90 { 91 public: 92 typedef size_t size_type; 93 typedef ptrdiff_t difference_type; 94 typedef _Tp* pointer; 95 typedef const _Tp* const_pointer; 96 typedef _Tp& reference; 97 typedef const _Tp& const_reference; 98 typedef _Tp value_type; 99 100 template<typename _Tp1> 101 struct rebind 102 { typedef allocator<_Tp1> other; }; 103 104 allocator() throw() { } 105 106 allocator(const allocator& __a) throw() 107 : __glibcxx_base_allocator<_Tp>(__a) { } 108 109 template<typename _Tp1> 110 allocator(const allocator<_Tp1>&) throw() { } 111 112 ~allocator() throw() { } 113 114 // Inherit everything else. 115 }; 116 117 template<typename _T1, typename _T2> 118 inline bool 119 operator==(const allocator<_T1>&, const allocator<_T2>&) 120 { return true; } 121 122 template<typename _Tp> 123 inline bool 124 operator==(const allocator<_Tp>&, const allocator<_Tp>&) 125 { return true; } 126 127 template<typename _T1, typename _T2> 128 inline bool 129 operator!=(const allocator<_T1>&, const allocator<_T2>&) 130 { return false; } 131 132 template<typename _Tp> 133 inline bool 134 operator!=(const allocator<_Tp>&, const allocator<_Tp>&) 135 { return false; } 136 137 /** 138 * @} 139 */ 140 141 // Inhibit implicit instantiations for required instantiations, 142 // which are defined via explicit instantiations elsewhere. 143 #if _GLIBCXX_EXTERN_TEMPLATE 144 extern template class allocator<char>; 145 extern template class allocator<wchar_t>; 146 #endif 147 148 // Undefine. 149 #undef __glibcxx_base_allocator 150 151 // To implement Option 3 of DR 431. 152 template<typename _Alloc, bool = __is_empty(_Alloc)> 153 struct __alloc_swap 154 { static void _S_do_it(_Alloc&, _Alloc&) { } }; 155 156 template<typename _Alloc> 157 struct __alloc_swap<_Alloc, false> 158 { 159 static void 160 _S_do_it(_Alloc& __one, _Alloc& __two) 161 { 162 // Precondition: swappable allocators. 163 if (__one != __two) 164 swap(__one, __two); 165 } 166 }; 167 168 // Optimize for stateless allocators. 169 template<typename _Alloc, bool = __is_empty(_Alloc)> 170 struct __alloc_neq 171 { 172 static bool 173 _S_do_it(const _Alloc&, const _Alloc&) 174 { return false; } 175 }; 176 177 template<typename _Alloc> 178 struct __alloc_neq<_Alloc, false> 179 { 180 static bool 181 _S_do_it(const _Alloc& __one, const _Alloc& __two) 182 { return __one != __two; } 183 }; 184 185 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 186 template<typename _Tp, bool 187 = __or_<is_copy_constructible<typename _Tp::value_type>, 188 is_nothrow_move_constructible<typename _Tp::value_type>>::value> 189 struct __shrink_to_fit_aux 190 { static bool _S_do_it(_Tp&) { return false; } }; 191 192 template<typename _Tp> 193 struct __shrink_to_fit_aux<_Tp, true> 194 { 195 static bool 196 _S_do_it(_Tp& __c) 197 { 198 __try 199 { 200 _Tp(__make_move_if_noexcept_iterator(__c.begin()), 201 __make_move_if_noexcept_iterator(__c.end()), 202 __c.get_allocator()).swap(__c); 203 return true; 204 } 205 __catch(...) 206 { return false; } 207 } 208 }; 209 210 // Declare uses_allocator so it can be specialized in <queue> etc. 211 template<typename, typename> 212 struct uses_allocator; 213 #endif 214 215 _GLIBCXX_END_NAMESPACE_VERSION 216 } // namespace std 217 218 #endif 219
