libstdc++-v3/include/ext/alloc_traits.h

   1 // Allocator traits -*- C++ -*-
   2
   3 // Copyright (C) 2011-2014 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 /** @file ext/alloc_traits.h
  26  *  This file is a GNU extension to the Standard C++ Library.
  27  */
  28
  29 #ifndef _EXT_ALLOC_TRAITS_H
  30 #define _EXT_ALLOC_TRAITS_H 1
  31
  32 #pragma GCC system_header
  33
  34 #if __cplusplus >= 201103L
  35 # include <bits/move.h>
  36 # include <bits/alloc_traits.h>
  37 #else
  38 # include <bits/allocator.h>  // for __alloc_swap
  39 #endif
  40
  41 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
  42 {
  43 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  44
  45 #if __cplusplus >= 201103L
  46   template<typename _Alloc>
  47     struct __allocator_always_compares_equal
  48     { static const bool value = false; };
  49
  50   template<typename _Alloc>
  51     const bool __allocator_always_compares_equal<_Alloc>::value;
  52
  53   template<typename _Tp>
  54     struct __allocator_always_compares_equal<std::allocator<_Tp>>
  55     { static const bool value = true; };
  56
  57   template<typename _Tp>
  58     const bool __allocator_always_compares_equal<std::allocator<_Tp>>::value;
  59
  60   template<typename, typename> struct array_allocator;
  61
  62   template<typename _Tp, typename _Array>
  63     struct __allocator_always_compares_equal<array_allocator<_Tp, _Array>>
  64     { static const bool value = true; };
  65
  66   template<typename _Tp, typename _Array>
  67     const bool
  68     __allocator_always_compares_equal<array_allocator<_Tp, _Array>>::value;
  69
  70   template<typename> struct bitmap_allocator;
  71
  72   template<typename _Tp>
  73     struct __allocator_always_compares_equal<bitmap_allocator<_Tp>>
  74     { static const bool value = true; };
  75
  76   template<typename _Tp>
  77     const bool __allocator_always_compares_equal<bitmap_allocator<_Tp>>::value;
  78
  79   template<typename> struct malloc_allocator;
  80
  81   template<typename _Tp>
  82     struct __allocator_always_compares_equal<malloc_allocator<_Tp>>
  83     { static const bool value = true; };
  84
  85   template<typename _Tp>
  86     const bool __allocator_always_compares_equal<malloc_allocator<_Tp>>::value;
  87
  88   template<typename> struct mt_allocator;
  89
  90   template<typename _Tp>
  91     struct __allocator_always_compares_equal<mt_allocator<_Tp>>
  92     { static const bool value = true; };
  93
  94   template<typename _Tp>
  95     const bool __allocator_always_compares_equal<mt_allocator<_Tp>>::value;
  96
  97   template<typename> struct new_allocator;
  98
  99   template<typename _Tp>
 100     struct __allocator_always_compares_equal<new_allocator<_Tp>>
 101     { static const bool value = true; };
 102
 103   template<typename _Tp>
 104     const bool __allocator_always_compares_equal<new_allocator<_Tp>>::value;
 105
 106   template<typename> struct pool_allocator;
 107
 108   template<typename _Tp>
 109     struct __allocator_always_compares_equal<pool_allocator<_Tp>>
 110     { static const bool value = true; };
 111
 112   template<typename _Tp>
 113     const bool __allocator_always_compares_equal<pool_allocator<_Tp>>::value;
 114 #endif
 115
 116 /**
 117  * @brief  Uniform interface to C++98 and C++0x allocators.
 118  * @ingroup allocators
 119 */
 120 template<typename _Alloc>
 121   struct __alloc_traits
 122 #if __cplusplus >= 201103L
 123   : std::allocator_traits<_Alloc>
 124 #endif
 125   {
 126     typedef _Alloc allocator_type;
 127 #if __cplusplus >= 201103L
 128     typedef std::allocator_traits<_Alloc>           _Base_type;
 129     typedef typename _Base_type::value_type         value_type;
 130     typedef typename _Base_type::pointer            pointer;
 131     typedef typename _Base_type::const_pointer      const_pointer;
 132     typedef typename _Base_type::size_type          size_type;
 133     typedef typename _Base_type::difference_type    difference_type;
 134     // C++0x allocators do not define reference or const_reference
 135     typedef value_type&                             reference;
 136     typedef const value_type&                       const_reference;
 137     using _Base_type::allocate;
 138     using _Base_type::deallocate;
 139     using _Base_type::construct;
 140     using _Base_type::destroy;
 141     using _Base_type::max_size;
 142
 143   private:
 144     template<typename _Ptr>
 145       struct __is_custom_pointer
 146       : std::integral_constant<bool, std::is_same<pointer, _Ptr>::value
 147                                      && !std::is_pointer<_Ptr>::value>
 148       { };
 149
 150   public:
 151     // overload construct for non-standard pointer types
 152     template<typename _Ptr, typename... _Args>
 153       static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type
 154       construct(_Alloc& __a, _Ptr __p, _Args&&... __args)
 155       {
 156         _Base_type::construct(__a, std::addressof(*__p),
 157                               std::forward<_Args>(__args)...);
 158       }
 159
 160     // overload destroy for non-standard pointer types
 161     template<typename _Ptr>
 162       static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type
 163       destroy(_Alloc& __a, _Ptr __p)
 164       { _Base_type::destroy(__a, std::addressof(*__p)); }
 165
 166     static _Alloc _S_select_on_copy(const _Alloc& __a)
 167     { return _Base_type::select_on_container_copy_construction(__a); }
 168
 169     static void _S_on_swap(_Alloc& __a, _Alloc& __b)
 170     { std::__alloc_on_swap(__a, __b); }
 171
 172     static constexpr bool _S_propagate_on_copy_assign()
 173     { return _Base_type::propagate_on_container_copy_assignment::value; }
 174
 175     static constexpr bool _S_propagate_on_move_assign()
 176     { return _Base_type::propagate_on_container_move_assignment::value; }
 177
 178     static constexpr bool _S_propagate_on_swap()
 179     { return _Base_type::propagate_on_container_swap::value; }
 180
 181     static constexpr bool _S_always_equal()
 182     { return __allocator_always_compares_equal<_Alloc>::value; }
 183
 184     static constexpr bool _S_nothrow_move()
 185     { return _S_propagate_on_move_assign() || _S_always_equal(); }
 186
 187     static constexpr bool _S_nothrow_swap()
 188     {
 189       using std::swap;
 190       return !_S_propagate_on_swap()
 191         || noexcept(swap(std::declval<_Alloc&>(), std::declval<_Alloc&>()));
 192     }
 193
 194     template<typename _Tp>
 195       struct rebind
 196       { typedef typename _Base_type::template rebind_alloc<_Tp> other; };
 197 #else
 198
 199     typedef typename _Alloc::pointer                pointer;
 200     typedef typename _Alloc::const_pointer          const_pointer;
 201     typedef typename _Alloc::value_type             value_type;
 202     typedef typename _Alloc::reference              reference;
 203     typedef typename _Alloc::const_reference        const_reference;
 204     typedef typename _Alloc::size_type              size_type;
 205     typedef typename _Alloc::difference_type        difference_type;
 206
 207     static pointer
 208     allocate(_Alloc& __a, size_type __n)
 209     { return __a.allocate(__n); }
 210
 211     static void deallocate(_Alloc& __a, pointer __p, size_type __n)
 212     { __a.deallocate(__p, __n); }
 213
 214     template<typename _Tp>
 215       static void construct(_Alloc& __a, pointer __p, const _Tp& __arg)
 216       { __a.construct(__p, __arg); }
 217
 218     static void destroy(_Alloc& __a, pointer __p)
 219     { __a.destroy(__p); }
 220
 221     static size_type max_size(const _Alloc& __a)
 222     { return __a.max_size(); }
 223
 224     static const _Alloc& _S_select_on_copy(const _Alloc& __a) { return __a; }
 225
 226     static void _S_on_swap(_Alloc& __a, _Alloc& __b)
 227     {
 228       // _GLIBCXX_RESOLVE_LIB_DEFECTS
 229       // 431. Swapping containers with unequal allocators.
 230       std::__alloc_swap<_Alloc>::_S_do_it(__a, __b);
 231     }
 232
 233     template<typename _Tp>
 234       struct rebind
 235       { typedef typename _Alloc::template rebind<_Tp>::other other; };
 236 #endif
 237   };
 238
 239 _GLIBCXX_END_NAMESPACE_VERSION
 240 } // namespace std
 241
 242 #endif