libstdc++
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00001 // Allocators -*- C++ -*- 00002 00003 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 00004 // 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 allocator.h 00040 * This is an internal header file, included by other library headers. 00041 * You should not attempt to use it directly. 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 _GLIBCXX_BEGIN_NAMESPACE(std) 00051 00052 /** 00053 * @defgroup allocators Allocators 00054 * @ingroup memory 00055 * 00056 * Classes encapsulating memory operations. 00057 */ 00058 00059 template<typename _Tp> 00060 class allocator; 00061 00062 /// allocator<void> specialization. 00063 template<> 00064 class allocator<void> 00065 { 00066 public: 00067 typedef size_t size_type; 00068 typedef ptrdiff_t difference_type; 00069 typedef void* pointer; 00070 typedef const void* const_pointer; 00071 typedef void value_type; 00072 00073 template<typename _Tp1> 00074 struct rebind 00075 { typedef allocator<_Tp1> other; }; 00076 }; 00077 00078 /** 00079 * @brief The "standard" allocator, as per [20.4]. 00080 * @ingroup allocators 00081 * 00082 * Further details: 00083 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt04ch11.html 00084 */ 00085 template<typename _Tp> 00086 class allocator: public __glibcxx_base_allocator<_Tp> 00087 { 00088 public: 00089 typedef size_t size_type; 00090 typedef ptrdiff_t difference_type; 00091 typedef _Tp* pointer; 00092 typedef const _Tp* const_pointer; 00093 typedef _Tp& reference; 00094 typedef const _Tp& const_reference; 00095 typedef _Tp value_type; 00096 00097 template<typename _Tp1> 00098 struct rebind 00099 { typedef allocator<_Tp1> other; }; 00100 00101 allocator() throw() { } 00102 00103 allocator(const allocator& __a) throw() 00104 : __glibcxx_base_allocator<_Tp>(__a) { } 00105 00106 template<typename _Tp1> 00107 allocator(const allocator<_Tp1>&) throw() { } 00108 00109 ~allocator() throw() { } 00110 00111 // Inherit everything else. 00112 }; 00113 00114 template<typename _T1, typename _T2> 00115 inline bool 00116 operator==(const allocator<_T1>&, const allocator<_T2>&) 00117 { return true; } 00118 00119 template<typename _Tp> 00120 inline bool 00121 operator==(const allocator<_Tp>&, const allocator<_Tp>&) 00122 { return true; } 00123 00124 template<typename _T1, typename _T2> 00125 inline bool 00126 operator!=(const allocator<_T1>&, const allocator<_T2>&) 00127 { return false; } 00128 00129 template<typename _Tp> 00130 inline bool 00131 operator!=(const allocator<_Tp>&, const allocator<_Tp>&) 00132 { return false; } 00133 00134 // Inhibit implicit instantiations for required instantiations, 00135 // which are defined via explicit instantiations elsewhere. 00136 // NB: This syntax is a GNU extension. 00137 #if _GLIBCXX_EXTERN_TEMPLATE 00138 extern template class allocator<char>; 00139 extern template class allocator<wchar_t>; 00140 #endif 00141 00142 // Undefine. 00143 #undef __glibcxx_base_allocator 00144 00145 // To implement Option 3 of DR 431. 00146 template<typename _Alloc, bool = __is_empty(_Alloc)> 00147 struct __alloc_swap 00148 { static void _S_do_it(_Alloc&, _Alloc&) { } }; 00149 00150 template<typename _Alloc> 00151 struct __alloc_swap<_Alloc, false> 00152 { 00153 static void 00154 _S_do_it(_Alloc& __one, _Alloc& __two) 00155 { 00156 // Precondition: swappable allocators. 00157 if (__one != __two) 00158 swap(__one, __two); 00159 } 00160 }; 00161 00162 // Optimize for stateless allocators. 00163 template<typename _Alloc, bool = __is_empty(_Alloc)> 00164 struct __alloc_neq 00165 { 00166 static bool 00167 _S_do_it(const _Alloc&, const _Alloc&) 00168 { return false; } 00169 }; 00170 00171 template<typename _Alloc> 00172 struct __alloc_neq<_Alloc, false> 00173 { 00174 static bool 00175 _S_do_it(const _Alloc& __one, const _Alloc& __two) 00176 { return __one != __two; } 00177 }; 00178 00179 _GLIBCXX_END_NAMESPACE 00180 00181 #endif