libstdc++
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00001 // Allocators -*- C++ -*- 00002 00003 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 00004 // 2011 Free Software Foundation, Inc. 00005 // 00006 // This file is part of the GNU ISO C++ Library. This library is free 00007 // software; you can redistribute it and/or modify it under the 00008 // terms of the GNU General Public License as published by the 00009 // Free Software Foundation; either version 3, or (at your option) 00010 // any later version. 00011 00012 // This library is distributed in the hope that it will be useful, 00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00015 // GNU General Public License for more details. 00016 00017 // Under Section 7 of GPL version 3, you are granted additional 00018 // permissions described in the GCC Runtime Library Exception, version 00019 // 3.1, as published by the Free Software Foundation. 00020 00021 // You should have received a copy of the GNU General Public License and 00022 // a copy of the GCC Runtime Library Exception along with this program; 00023 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00024 // <http://www.gnu.org/licenses/>. 00025 00026 /* 00027 * Copyright (c) 1996-1997 00028 * Silicon Graphics Computer Systems, Inc. 00029 * 00030 * Permission to use, copy, modify, distribute and sell this software 00031 * and its documentation for any purpose is hereby granted without fee, 00032 * provided that the above copyright notice appear in all copies and 00033 * that both that copyright notice and this permission notice appear 00034 * in supporting documentation. Silicon Graphics makes no 00035 * representations about the suitability of this software for any 00036 * purpose. It is provided "as is" without express or implied warranty. 00037 */ 00038 00039 /** @file bits/allocator.h 00040 * This is an internal header file, included by other library headers. 00041 * Do not attempt to use it directly. @headername{memory} 00042 */ 00043 00044 #ifndef _ALLOCATOR_H 00045 #define _ALLOCATOR_H 1 00046 00047 // Define the base class to std::allocator. 00048 #include <bits/c++allocator.h> 00049 00050 namespace std _GLIBCXX_VISIBILITY(default) 00051 { 00052 _GLIBCXX_BEGIN_NAMESPACE_VERSION 00053 00054 /** 00055 * @defgroup allocators Allocators 00056 * @ingroup memory 00057 * 00058 * Classes encapsulating memory operations. 00059 * 00060 * @{ 00061 */ 00062 00063 template<typename _Tp> 00064 class allocator; 00065 00066 /// allocator<void> specialization. 00067 template<> 00068 class allocator<void> 00069 { 00070 public: 00071 typedef size_t size_type; 00072 typedef ptrdiff_t difference_type; 00073 typedef void* pointer; 00074 typedef const void* const_pointer; 00075 typedef void value_type; 00076 00077 template<typename _Tp1> 00078 struct rebind 00079 { typedef allocator<_Tp1> other; }; 00080 }; 00081 00082 /** 00083 * @brief The @a standard allocator, as per [20.4]. 00084 * 00085 * See http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt04ch11.html 00086 * for further details. 00087 */ 00088 template<typename _Tp> 00089 class allocator: public __glibcxx_base_allocator<_Tp> 00090 { 00091 public: 00092 typedef size_t size_type; 00093 typedef ptrdiff_t difference_type; 00094 typedef _Tp* pointer; 00095 typedef const _Tp* const_pointer; 00096 typedef _Tp& reference; 00097 typedef const _Tp& const_reference; 00098 typedef _Tp value_type; 00099 00100 template<typename _Tp1> 00101 struct rebind 00102 { typedef allocator<_Tp1> other; }; 00103 00104 allocator() throw() { } 00105 00106 allocator(const allocator& __a) throw() 00107 : __glibcxx_base_allocator<_Tp>(__a) { } 00108 00109 template<typename _Tp1> 00110 allocator(const allocator<_Tp1>&) throw() { } 00111 00112 ~allocator() throw() { } 00113 00114 // Inherit everything else. 00115 }; 00116 00117 template<typename _T1, typename _T2> 00118 inline bool 00119 operator==(const allocator<_T1>&, const allocator<_T2>&) 00120 { return true; } 00121 00122 template<typename _Tp> 00123 inline bool 00124 operator==(const allocator<_Tp>&, const allocator<_Tp>&) 00125 { return true; } 00126 00127 template<typename _T1, typename _T2> 00128 inline bool 00129 operator!=(const allocator<_T1>&, const allocator<_T2>&) 00130 { return false; } 00131 00132 template<typename _Tp> 00133 inline bool 00134 operator!=(const allocator<_Tp>&, const allocator<_Tp>&) 00135 { return false; } 00136 00137 /** 00138 * @} 00139 */ 00140 00141 // Inhibit implicit instantiations for required instantiations, 00142 // which are defined via explicit instantiations elsewhere. 00143 #if _GLIBCXX_EXTERN_TEMPLATE 00144 extern template class allocator<char>; 00145 extern template class allocator<wchar_t>; 00146 #endif 00147 00148 // Undefine. 00149 #undef __glibcxx_base_allocator 00150 00151 // To implement Option 3 of DR 431. 00152 template<typename _Alloc, bool = __is_empty(_Alloc)> 00153 struct __alloc_swap 00154 { static void _S_do_it(_Alloc&, _Alloc&) { } }; 00155 00156 template<typename _Alloc> 00157 struct __alloc_swap<_Alloc, false> 00158 { 00159 static void 00160 _S_do_it(_Alloc& __one, _Alloc& __two) 00161 { 00162 // Precondition: swappable allocators. 00163 if (__one != __two) 00164 swap(__one, __two); 00165 } 00166 }; 00167 00168 // Optimize for stateless allocators. 00169 template<typename _Alloc, bool = __is_empty(_Alloc)> 00170 struct __alloc_neq 00171 { 00172 static bool 00173 _S_do_it(const _Alloc&, const _Alloc&) 00174 { return false; } 00175 }; 00176 00177 template<typename _Alloc> 00178 struct __alloc_neq<_Alloc, false> 00179 { 00180 static bool 00181 _S_do_it(const _Alloc& __one, const _Alloc& __two) 00182 { return __one != __two; } 00183 }; 00184 00185 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 00186 template<typename _Tp, bool 00187 = __or_<is_copy_constructible<typename _Tp::value_type>, 00188 is_nothrow_move_constructible<typename _Tp::value_type>>::value> 00189 struct __shrink_to_fit_aux 00190 { static bool _S_do_it(_Tp&) { return false; } }; 00191 00192 template<typename _Tp> 00193 struct __shrink_to_fit_aux<_Tp, true> 00194 { 00195 static bool 00196 _S_do_it(_Tp& __c) 00197 { 00198 __try 00199 { 00200 _Tp(__make_move_if_noexcept_iterator(__c.begin()), 00201 __make_move_if_noexcept_iterator(__c.end()), 00202 __c.get_allocator()).swap(__c); 00203 return true; 00204 } 00205 __catch(...) 00206 { return false; } 00207 } 00208 }; 00209 00210 // Declare uses_allocator so it can be specialized in <queue> etc. 00211 template<typename, typename> 00212 struct uses_allocator; 00213 #endif 00214 00215 _GLIBCXX_END_NAMESPACE_VERSION 00216 } // namespace std 00217 00218 #endif