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

   1 // Allocator traits -*- C++ -*-
   2
   3 // Copyright (C) 2011-2012 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 std _GLIBCXX_VISIBILITY(default)
  42 {
  43 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  44   template<typename> struct allocator;
  45 _GLIBCXX_END_NAMESPACE_VERSION
  46 } // namespace
  47
  48 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
  49 {
  50 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  51
  52 #if __cplusplus >= 201103L
  53   template<typename _Alloc>
  54     struct __allocator_always_compares_equal
  55     { static const bool value = false; };
  56
  57   template<typename _Alloc>
  58     const bool __allocator_always_compares_equal<_Alloc>::value;
  59
  60   template<typename _Tp>
  61     struct __allocator_always_compares_equal<std::allocator<_Tp>>
  62     { static const bool value = true; };
  63
  64   template<typename _Tp>
  65     const bool __allocator_always_compares_equal<std::allocator<_Tp>>::value;
  66
  67   template<typename, typename> struct array_allocator;
  68
  69   template<typename _Tp, typename _Array>
  70     struct __allocator_always_compares_equal<array_allocator<_Tp, _Array>>
  71     { static const bool value = true; };
  72
  73   template<typename _Tp, typename _Array>
  74     const bool
  75     __allocator_always_compares_equal<array_allocator<_Tp, _Array>>::value;
  76
  77   template<typename> struct bitmap_allocator;
  78
  79   template<typename _Tp>
  80     struct __allocator_always_compares_equal<bitmap_allocator<_Tp>>
  81     { static const bool value = true; };
  82
  83   template<typename _Tp>
  84     const bool __allocator_always_compares_equal<bitmap_allocator<_Tp>>::value;
  85
  86   template<typename> struct malloc_allocator;
  87
  88   template<typename _Tp>
  89     struct __allocator_always_compares_equal<malloc_allocator<_Tp>>
  90     { static const bool value = true; };
  91
  92   template<typename _Tp>
  93     const bool __allocator_always_compares_equal<malloc_allocator<_Tp>>::value;
  94
  95   template<typename> struct mt_allocator;
  96
  97   template<typename _Tp>
  98     struct __allocator_always_compares_equal<mt_allocator<_Tp>>
  99     { static const bool value = true; };
 100
 101   template<typename _Tp>
 102     const bool __allocator_always_compares_equal<mt_allocator<_Tp>>::value;
 103
 104   template<typename> struct new_allocator;
 105
 106   template<typename _Tp>
 107     struct __allocator_always_compares_equal<new_allocator<_Tp>>
 108     { static const bool value = true; };
 109
 110   template<typename _Tp>
 111     const bool __allocator_always_compares_equal<new_allocator<_Tp>>::value;
 112
 113   template<typename> struct pool_allocator;
 114
 115   template<typename _Tp>
 116     struct __allocator_always_compares_equal<pool_allocator<_Tp>>
 117     { static const bool value = true; };
 118
 119   template<typename _Tp>
 120     const bool __allocator_always_compares_equal<pool_allocator<_Tp>>::value;
 121 #endif
 122
 123 /**
 124  * @brief  Uniform interface to C++98 and C++0x allocators.
 125  * @ingroup allocators
 126 */
 127 template<typename _Alloc>
 128   struct __alloc_traits
 129 #if __cplusplus >= 201103L
 130   : std::allocator_traits<_Alloc>
 131 #endif
 132   {
 133     typedef _Alloc allocator_type;
 134 #if __cplusplus >= 201103L
 135     typedef std::allocator_traits<_Alloc>           _Base_type;
 136     typedef typename _Base_type::value_type         value_type;
 137     typedef typename _Base_type::pointer            pointer;
 138     typedef typename _Base_type::const_pointer      const_pointer;
 139     typedef typename _Base_type::size_type          size_type;
 140     typedef typename _Base_type::difference_type    difference_type;
 141     // C++0x allocators do not define reference or const_reference
 142     typedef value_type&                             reference;
 143     typedef const value_type&                       const_reference;
 144     using _Base_type::allocate;
 145     using _Base_type::deallocate;
 146     using _Base_type::construct;
 147     using _Base_type::destroy;
 148     using _Base_type::max_size;
 149
 150   private:
 151     template<typename _Ptr>
 152       struct __is_custom_pointer
 153       : std::integral_constant<bool, std::is_same<pointer, _Ptr>::value
 154                                      && !std::is_pointer<_Ptr>::value>
 155       { };
 156
 157   public:
 158     // overload construct for non-standard pointer types
 159     template<typename _Ptr, typename... _Args>
 160       static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type
 161       construct(_Alloc& __a, _Ptr __p, _Args&&... __args)
 162       {
 163         _Base_type::construct(__a, std::addressof(*__p),
 164                               std::forward<_Args>(__args)...);
 165       }
 166
 167     // overload destroy for non-standard pointer types
 168     template<typename _Ptr>
 169       static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type
 170       destroy(_Alloc& __a, _Ptr __p)
 171       { _Base_type::destroy(__a, std::addressof(*__p)); }
 172
 173     static _Alloc _S_select_on_copy(const _Alloc& __a)
 174     { return _Base_type::select_on_container_copy_construction(__a); }
 175
 176     static void _S_on_swap(_Alloc& __a, _Alloc& __b)
 177     { std::__alloc_on_swap(__a, __b); }
 178
 179     static constexpr bool _S_propagate_on_copy_assign()
 180     { return _Base_type::propagate_on_container_copy_assignment::value; }
 181
 182     static constexpr bool _S_propagate_on_move_assign()
 183     { return _Base_type::propagate_on_container_move_assignment::value; }
 184
 185     static constexpr bool _S_propagate_on_swap()
 186     { return _Base_type::propagate_on_container_swap::value; }
 187
 188     static constexpr bool _S_always_equal()
 189     { return __allocator_always_compares_equal<_Alloc>::value; }
 190
 191     static constexpr bool _S_nothrow_move()
 192     { return _S_propagate_on_move_assign() || _S_always_equal(); }
 193
 194     static constexpr bool _S_nothrow_swap()
 195     {
 196       using std::swap;
 197       return !_S_propagate_on_swap()
 198         || noexcept(swap(std::declval<_Alloc&>(), std::declval<_Alloc&>()));
 199     }
 200
 201     template<typename _Tp>
 202       struct rebind
 203       { typedef typename _Base_type::template rebind_alloc<_Tp> other; };
 204 #else
 205
 206     typedef typename _Alloc::pointer                pointer;
 207     typedef typename _Alloc::const_pointer          const_pointer;
 208     typedef typename _Alloc::value_type             value_type;
 209     typedef typename _Alloc::reference              reference;
 210     typedef typename _Alloc::const_reference        const_reference;
 211     typedef typename _Alloc::size_type              size_type;
 212     typedef typename _Alloc::difference_type        difference_type;
 213
 214     static pointer
 215     allocate(_Alloc& __a, size_type __n)
 216     { return __a.allocate(__n); }
 217
 218     static void deallocate(_Alloc& __a, pointer __p, size_type __n)
 219     { __a.deallocate(__p, __n); }
 220
 221     template<typename _Tp>
 222       static void construct(_Alloc& __a, pointer __p, const _Tp& __arg)
 223       { __a.construct(__p, __arg); }
 224
 225     static void destroy(_Alloc& __a, pointer __p)
 226     { __a.destroy(__p); }
 227
 228     static size_type max_size(const _Alloc& __a)
 229     { return __a.max_size(); }
 230
 231     static const _Alloc& _S_select_on_copy(const _Alloc& __a) { return __a; }
 232
 233     static void _S_on_swap(_Alloc& __a, _Alloc& __b)
 234     {
 235       // _GLIBCXX_RESOLVE_LIB_DEFECTS
 236       // 431. Swapping containers with unequal allocators.
 237       std::__alloc_swap<_Alloc>::_S_do_it(__a, __b);
 238     }
 239
 240     template<typename _Tp>
 241       struct rebind
 242       { typedef typename _Alloc::template rebind<_Tp>::other other; };
 243 #endif
 244   };
 245
 246 _GLIBCXX_END_NAMESPACE_VERSION
 247 } // namespace
 248
 249 #endif