1// Allocator that wraps operator new -*- C++ -*-
2
3// Copyright (C) 2001, 2002, 2003, 2004, 2005, 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/** @file ext/new_allocator.h
27 *  This file is a GNU extension to the Standard C++ Library.
28 */
29
30#ifndef _NEW_ALLOCATOR_H
31#define _NEW_ALLOCATOR_H 1
32
33#include <new>
34#include <bits/functexcept.h>
35#include <bits/move.h>
36
37_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
38
39  using std::size_t;
40  using std::ptrdiff_t;
41
42  /**
43   *  @brief  An allocator that uses global new, as per [20.4].
44   *  @ingroup allocators
45   *
46   *  This is precisely the allocator defined in the C++ Standard.
47   *    - all allocation calls operator new
48   *    - all deallocation calls operator delete
49   */
50  template<typename _Tp>
51    class new_allocator
52    {
53    public:
54      typedef size_t     size_type;
55      typedef ptrdiff_t  difference_type;
56      typedef _Tp*       pointer;
57      typedef const _Tp* const_pointer;
58      typedef _Tp&       reference;
59      typedef const _Tp& const_reference;
60      typedef _Tp        value_type;
61
62      template<typename _Tp1>
63        struct rebind
64        { typedef new_allocator<_Tp1> other; };
65
66      new_allocator() throw() { }
67
68      new_allocator(const new_allocator&) throw() { }
69
70      template<typename _Tp1>
71        new_allocator(const new_allocator<_Tp1>&) throw() { }
72
73      ~new_allocator() throw() { }
74
75      pointer
76      address(reference __x) const { return &__x; }
77
78      const_pointer
79      address(const_reference __x) const { return &__x; }
80
81      // NB: __n is permitted to be 0.  The C++ standard says nothing
82      // about what the return value is when __n == 0.
83      pointer
84      allocate(size_type __n, const void* = 0)
85      {
86	if (__builtin_expect(__n > this->max_size(), false))
87	  std::__throw_bad_alloc();
88
89	return static_cast<_Tp*>(::operator new(__n * sizeof(_Tp)));
90      }
91
92      // __p is not permitted to be a null pointer.
93      void
94      deallocate(pointer __p, size_type)
95      { ::operator delete(__p); }
96
97      size_type
98      max_size() const throw()
99      { return size_t(-1) / sizeof(_Tp); }
100
101      // _GLIBCXX_RESOLVE_LIB_DEFECTS
102      // 402. wrong new expression in [some_] allocator::construct
103      void
104      construct(pointer __p, const _Tp& __val)
105      { ::new((void *)__p) _Tp(__val); }
106
107#ifdef __GXX_EXPERIMENTAL_CXX0X__
108      template<typename... _Args>
109        void
110        construct(pointer __p, _Args&&... __args)
111	{ ::new((void *)__p) _Tp(std::forward<_Args>(__args)...); }
112#endif
113
114      void
115      destroy(pointer __p) { __p->~_Tp(); }
116    };
117
118  template<typename _Tp>
119    inline bool
120    operator==(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
121    { return true; }
122
123  template<typename _Tp>
124    inline bool
125    operator!=(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
126    { return false; }
127
128_GLIBCXX_END_NAMESPACE
129
130#endif
131