new_allocator.h revision 132720 
1// Allocator that wraps operator new -*- C++ -*-
2
3// Copyright (C) 2001, 2002, 2003, 2004 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 2, 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// You should have received a copy of the GNU General Public License along
17// with this library; see the file COPYING.  If not, write to the Free
18// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
19// USA.
20
21// As a special exception, you may use this file as part of a free software
22// library without restriction.  Specifically, if other files instantiate
23// templates or use macros or inline functions from this file, or you compile
24// this file and link it with other files to produce an executable, this
25// file does not by itself cause the resulting executable to be covered by
26// the GNU General Public License.  This exception does not however
27// invalidate any other reasons why the executable file might be covered by
28// the GNU General Public License.
29
30#ifndef _NEW_ALLOCATOR_H
31#define _NEW_ALLOCATOR_H 1
32
33#include <new>
34
35namespace __gnu_cxx
36{
37  /**
38   *  @brief  An allocator that uses global new, as per [20.4].
39   *
40   *  This is precisely the allocator defined in the C++ Standard.
41   *    - all allocation calls operator new
42   *    - all deallocation calls operator delete
43   *
44   *  (See @link Allocators allocators info @endlink for more.)
45   */
46  template<typename _Tp>
47    class new_allocator
48    {
49    public:
50      typedef size_t     size_type;
51      typedef ptrdiff_t  difference_type;
52      typedef _Tp*       pointer;
53      typedef const _Tp* const_pointer;
54      typedef _Tp&       reference;
55      typedef const _Tp& const_reference;
56      typedef _Tp        value_type;
57
58      template<typename _Tp1>
59        struct rebind
60        { typedef new_allocator<_Tp1> other; };
61
62      new_allocator() throw() { }
63
64      new_allocator(const new_allocator&) throw() { }
65
66      template<typename _Tp1>
67        new_allocator(const new_allocator<_Tp1>&) throw() { }
68
69      ~new_allocator() throw() { }
70
71      pointer
72      address(reference __x) const { return &__x; }
73
74      const_pointer
75      address(const_reference __x) const { return &__x; }
76
77      // NB: __n is permitted to be 0.  The C++ standard says nothing
78      // about what the return value is when __n == 0.
79      pointer
80      allocate(size_type __n, const void* = 0)
81      { return static_cast<_Tp*>(::operator new(__n * sizeof(_Tp))); }
82
83      // __p is not permitted to be a null pointer.
84      void
85      deallocate(pointer __p, size_type)
86      { ::operator delete(__p); }
87
88      size_type
89      max_size() const throw()
90      { return size_t(-1) / sizeof(_Tp); }
91
92      // _GLIBCXX_RESOLVE_LIB_DEFECTS
93      // 402. wrong new expression in [some_] allocator::construct
94      void
95      construct(pointer __p, const _Tp& __val)
96      { ::new(__p) _Tp(__val); }
97
98      void
99      destroy(pointer __p) { __p->~_Tp(); }
100    };
101
102  template<typename _Tp>
103    inline bool
104    operator==(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
105    { return true; }
106
107  template<typename _Tp>
108    inline bool
109    operator!=(const new_allocator<_Tp>&, const new_allocator<_Tp>&)
110    { return false; }
111} // namespace __gnu_cxx
112
113#endif
114