mingw/lib/gcc/mingw32/4.4.0/include/c++/bits/allocator.h

   1 // Allocators -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
   4 // 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 allocator.h
  40  *  This is an internal header file, included by other library headers.
  41  *  You should not attempt to use it directly.
  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 _GLIBCXX_BEGIN_NAMESPACE(std)
  51
  52   /**
  53    * @defgroup allocators Allocators
  54    * @ingroup memory
  55    *
  56    * Classes encapsulating memory operations.
  57    */
  58
  59   template<typename _Tp>
  60     class allocator;
  61
  62   /// allocator<void> specialization.
  63   template<>
  64     class allocator<void>
  65     {
  66     public:
  67       typedef size_t      size_type;
  68       typedef ptrdiff_t   difference_type;
  69       typedef void*       pointer;
  70       typedef const void* const_pointer;
  71       typedef void        value_type;
  72
  73       template<typename _Tp1>
  74         struct rebind
  75         { typedef allocator<_Tp1> other; };
  76     };
  77
  78   /**
  79    * @brief  The "standard" allocator, as per [20.4].
  80    * @ingroup allocators
  81    *
  82    *  Further details:
  83    *  http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt04ch11.html
  84    */
  85   template<typename _Tp>
  86     class allocator: public __glibcxx_base_allocator<_Tp>
  87     {
  88    public:
  89       typedef size_t     size_type;
  90       typedef ptrdiff_t  difference_type;
  91       typedef _Tp*       pointer;
  92       typedef const _Tp* const_pointer;
  93       typedef _Tp&       reference;
  94       typedef const _Tp& const_reference;
  95       typedef _Tp        value_type;
  96
  97       template<typename _Tp1>
  98         struct rebind
  99         { typedef allocator<_Tp1> other; };
 100
 101       allocator() throw() { }
 102
 103       allocator(const allocator& __a) throw()
 104       : __glibcxx_base_allocator<_Tp>(__a) { }
 105
 106       template<typename _Tp1>
 107         allocator(const allocator<_Tp1>&) throw() { }
 108
 109       ~allocator() throw() { }
 110
 111       // Inherit everything else.
 112     };
 113
 114   template<typename _T1, typename _T2>
 115     inline bool
 116     operator==(const allocator<_T1>&, const allocator<_T2>&)
 117     { return true; }
 118
 119   template<typename _Tp>
 120     inline bool
 121     operator==(const allocator<_Tp>&, const allocator<_Tp>&)
 122     { return true; }
 123
 124   template<typename _T1, typename _T2>
 125     inline bool
 126     operator!=(const allocator<_T1>&, const allocator<_T2>&)
 127     { return false; }
 128
 129   template<typename _Tp>
 130     inline bool
 131     operator!=(const allocator<_Tp>&, const allocator<_Tp>&)
 132     { return false; }
 133
 134   // Inhibit implicit instantiations for required instantiations,
 135   // which are defined via explicit instantiations elsewhere.
 136   // NB: This syntax is a GNU extension.
 137 #if _GLIBCXX_EXTERN_TEMPLATE
 138   extern template class allocator<char>;
 139   extern template class allocator<wchar_t>;
 140 #endif
 141
 142   // Undefine.
 143 #undef __glibcxx_base_allocator
 144
 145   // To implement Option 3 of DR 431.
 146   template<typename _Alloc, bool = __is_empty(_Alloc)>
 147     struct __alloc_swap
 148     { static void _S_do_it(_Alloc&, _Alloc&) { } };
 149
 150   template<typename _Alloc>
 151     struct __alloc_swap<_Alloc, false>
 152     {
 153       static void
 154       _S_do_it(_Alloc& __one, _Alloc& __two)
 155       {
 156         // Precondition: swappable allocators.
 157         if (__one != __two)
 158           swap(__one, __two);
 159       }
 160     };
 161
 162   // Optimize for stateless allocators.
 163   template<typename _Alloc, bool = __is_empty(_Alloc)>
 164     struct __alloc_neq
 165     {
 166       static bool
 167       _S_do_it(const _Alloc&, const _Alloc&)
 168       { return false; }
 169     };
 170
 171   template<typename _Alloc>
 172     struct __alloc_neq<_Alloc, false>
 173     {
 174       static bool
 175       _S_do_it(const _Alloc& __one, const _Alloc& __two)
 176       { return __one != __two; }
 177     };
 178
 179 _GLIBCXX_END_NAMESPACE
 180
 181 #endif