1// Allocator that wraps operator new -*- C++ -*-
2
3// Copyright (C) 2001-2015 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/new_allocator.h
26 *  This file is a GNU extension to the Standard C++ Library.
27 */
28
29#ifndef _NEW_ALLOCATOR_H
30#define _NEW_ALLOCATOR_H 1
31
32#include <bits/c++config.h>
33#include <new>
34#include <bits/functexcept.h>
35#include <bits/move.h>
36#if __cplusplus >= 201103L
37#include <type_traits>
38#endif
39
40namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
41{
42_GLIBCXX_BEGIN_NAMESPACE_VERSION
43
44  using std::size_t;
45  using std::ptrdiff_t;
46
47  /**
48   *  @brief  An allocator that uses global new, as per [20.4].
49   *  @ingroup allocators
50   *
51   *  This is precisely the allocator defined in the C++ Standard.
52   *    - all allocation calls operator new
53   *    - all deallocation calls operator delete
54   *
55   *  @tparam  _Tp  Type of allocated object.
56   */
57  template<typename _Tp>
58    class new_allocator
59    {
60    public:
61      typedef size_t     size_type;
62      typedef ptrdiff_t  difference_type;
63      typedef _Tp*       pointer;
64      typedef const _Tp* const_pointer;
65      typedef _Tp&       reference;
66      typedef const _Tp& const_reference;
67      typedef _Tp        value_type;
68
69      template<typename _Tp1>
70        struct rebind
71        { typedef new_allocator<_Tp1> other; };
72
73#if __cplusplus >= 201103L
74      // _GLIBCXX_RESOLVE_LIB_DEFECTS
75      // 2103. propagate_on_container_move_assignment
76      typedef std::true_type propagate_on_container_move_assignment;
77#endif
78
79      new_allocator() _GLIBCXX_USE_NOEXCEPT { }
80
81      new_allocator(const new_allocator&) _GLIBCXX_USE_NOEXCEPT { }
82
83      template<typename _Tp1>
84        new_allocator(const new_allocator<_Tp1>&) _GLIBCXX_USE_NOEXCEPT { }
85
86      ~new_allocator() _GLIBCXX_USE_NOEXCEPT { }
87
88      pointer
89      address(reference __x) const _GLIBCXX_NOEXCEPT
90      { return std::__addressof(__x); }
91
92      const_pointer
93      address(const_reference __x) const _GLIBCXX_NOEXCEPT
94      { return std::__addressof(__x); }
95
96      // NB: __n is permitted to be 0.  The C++ standard says nothing
97      // about what the return value is when __n == 0.
98      pointer
99      allocate(size_type __n, const void* = 0)
100      {
101	if (__n > this->max_size())
102	  std::__throw_bad_alloc();
103
104	return static_cast<_Tp*>(::operator new(__n * sizeof(_Tp)));
105      }
106
107      // __p is not permitted to be a null pointer.
108      void
109      deallocate(pointer __p, size_type)
110      { ::operator delete(__p); }
111
112      size_type
113      max_size() const _GLIBCXX_USE_NOEXCEPT
114      { return size_t(-1) / sizeof(_Tp); }
115
116#if __cplusplus >= 201103L
117      template<typename _Up, typename... _Args>
118        void
119        construct(_Up* __p, _Args&&... __args)
120	{ ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
121
122      template<typename _Up>
123        void
124        destroy(_Up* __p) { __p->~_Up(); }
125#else
126      // _GLIBCXX_RESOLVE_LIB_DEFECTS
127      // 402. wrong new expression in [some_] allocator::construct
128      void
129      construct(pointer __p, const _Tp& __val)
130      { ::new((void *)__p) _Tp(__val); }
131
132      void
133      destroy(pointer __p) { __p->~_Tp(); }
134#endif
135    };
136
137  template<typename _Tp>
138    inline bool
139    operator==(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
140    { return true; }
141
142  template<typename _Tp>
143    inline bool
144    operator!=(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
145    { return false; }
146
147_GLIBCXX_END_NAMESPACE_VERSION
148} // namespace
149
150#endif
151