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

   1 // array allocator -*- C++ -*-
   2
   3 // Copyright (C) 2004-2016 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/array_allocator.h
  26  *  This file is a GNU extension to the Standard C++ Library.
  27  */
  28
  29 #ifndef _ARRAY_ALLOCATOR_H
  30 #define _ARRAY_ALLOCATOR_H 1
  31
  32 #include <bits/c++config.h>
  33 #include <new>
  34 #include <bits/functexcept.h>
  35 #include <tr1/array>
  36 #include <bits/move.h>
  37 #if __cplusplus >= 201103L
  38 #include <type_traits>
  39 #endif
  40
  41 // Suppress deprecated warning for this file.
  42 #pragma GCC diagnostic push
  43 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
  44
  45 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
  46 {
  47 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  48
  49  using std::size_t;
  50  using std::ptrdiff_t;
  51
  52   /// Base class.
  53  template<typename _Tp>
  54     class array_allocator_base
  55     {
  56     public:
  57       typedef size_t            size_type;
  58       typedef ptrdiff_t         difference_type;
  59       typedef _Tp*              pointer;
  60       typedef const _Tp*        const_pointer;
  61       typedef _Tp&              reference;
  62       typedef const _Tp&        const_reference;
  63       typedef _Tp               value_type;
  64
  65       pointer
  66       address(reference __x) const _GLIBCXX_NOEXCEPT
  67       { return std::__addressof(__x); }
  68
  69       const_pointer
  70       address(const_reference __x) const _GLIBCXX_NOEXCEPT
  71       { return std::__addressof(__x); }
  72
  73       void
  74       deallocate(pointer, size_type)
  75       {
  76         // Does nothing.
  77       }
  78
  79       size_type
  80       max_size() const _GLIBCXX_USE_NOEXCEPT
  81       { return size_t(-1) / sizeof(_Tp); }
  82
  83 #if __cplusplus >= 201103L
  84       template<typename _Up, typename... _Args>
  85         void
  86         construct(_Up* __p, _Args&&... __args)
  87         { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
  88
  89       template<typename _Up>
  90         void
  91         destroy(_Up* __p) { __p->~_Up(); }
  92 #else
  93       // _GLIBCXX_RESOLVE_LIB_DEFECTS
  94       // 402. wrong new expression in [some_] allocator::construct
  95       void
  96       construct(pointer __p, const _Tp& __val)
  97       { ::new((void *)__p) value_type(__val); }
  98
  99       void
 100       destroy(pointer __p) { __p->~_Tp(); }
 101 #endif
 102     } _GLIBCXX_DEPRECATED;
 103
 104   /**
 105    *  @brief  An allocator that uses previously allocated memory.
 106    *  This memory can be externally, globally, or otherwise allocated.
 107    *  @ingroup allocators
 108    */
 109   template<typename _Tp, typename _Array = std::tr1::array<_Tp, 1> >
 110     class array_allocator : public array_allocator_base<_Tp>
 111     {
 112     public:
 113       typedef size_t            size_type;
 114       typedef ptrdiff_t         difference_type;
 115       typedef _Tp*              pointer;
 116       typedef const _Tp*        const_pointer;
 117       typedef _Tp&              reference;
 118       typedef const _Tp&        const_reference;
 119       typedef _Tp               value_type;
 120       typedef _Array            array_type;
 121
 122 #if __cplusplus >= 201103L
 123       // _GLIBCXX_RESOLVE_LIB_DEFECTS
 124       // 2103. std::allocator propagate_on_container_move_assignment
 125       typedef std::true_type propagate_on_container_move_assignment;
 126
 127       typedef std::true_type is_always_equal;
 128 #endif
 129
 130     private:
 131       array_type*       _M_array;
 132       size_type         _M_used;
 133
 134     public:
 135      template<typename _Tp1, typename _Array1 = _Array>
 136         struct rebind
 137         {
 138           typedef array_allocator<_Tp1, _Array1> other _GLIBCXX_DEPRECATED;
 139         } _GLIBCXX_DEPRECATED;
 140
 141       array_allocator(array_type* __array = 0) _GLIBCXX_USE_NOEXCEPT
 142       : _M_array(__array), _M_used(size_type()) { }
 143
 144       array_allocator(const array_allocator& __o) _GLIBCXX_USE_NOEXCEPT
 145       : _M_array(__o._M_array), _M_used(__o._M_used) { }
 146
 147       template<typename _Tp1, typename _Array1>
 148         array_allocator(const array_allocator<_Tp1, _Array1>&)
 149         _GLIBCXX_USE_NOEXCEPT
 150         : _M_array(0), _M_used(size_type()) { }
 151
 152       ~array_allocator() _GLIBCXX_USE_NOEXCEPT { }
 153
 154       pointer
 155       allocate(size_type __n, const void* = 0)
 156       {
 157         if (_M_array == 0 || _M_used + __n > _M_array->size())
 158           std::__throw_bad_alloc();
 159         pointer __ret = _M_array->begin() + _M_used;
 160         _M_used += __n;
 161         return __ret;
 162       }
 163     } _GLIBCXX_DEPRECATED;
 164
 165   template<typename _Tp, typename _Array>
 166     inline bool
 167     operator==(const array_allocator<_Tp, _Array>&,
 168                const array_allocator<_Tp, _Array>&)
 169     { return true; }
 170
 171   template<typename _Tp, typename _Array>
 172     inline bool
 173     operator!=(const array_allocator<_Tp, _Array>&,
 174                const array_allocator<_Tp, _Array>&)
 175     { return false; }
 176
 177 _GLIBCXX_END_NAMESPACE_VERSION
 178 } // namespace
 179
 180 #pragma GCC diagnostic pop
 181
 182 #endif