1// Safe sequence implementation  -*- C++ -*-
2
3// Copyright (C) 2003, 2004, 2005
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 2, 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// You should have received a copy of the GNU General Public License along
18// with this library; see the file COPYING.  If not, write to the Free
19// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
20// USA.
21
22// As a special exception, you may use this file as part of a free software
23// library without restriction.  Specifically, if other files instantiate
24// templates or use macros or inline functions from this file, or you compile
25// this file and link it with other files to produce an executable, this
26// file does not by itself cause the resulting executable to be covered by
27// the GNU General Public License.  This exception does not however
28// invalidate any other reasons why the executable file might be covered by
29// the GNU General Public License.
30
31#ifndef _GLIBCXX_DEBUG_SAFE_SEQUENCE_H
32#define _GLIBCXX_DEBUG_SAFE_SEQUENCE_H 1
33
34#include <debug/debug.h>
35#include <debug/macros.h>
36#include <debug/functions.h>
37#include <debug/safe_base.h>
38
39namespace __gnu_debug
40{
41  template<typename _Iterator, typename _Sequence>
42    class _Safe_iterator;
43
44  /** A simple function object that returns true if the passed-in
45   *  value is not equal to the stored value. It saves typing over
46   *  using both bind1st and not_equal.
47   */
48  template<typename _Type>
49    class _Not_equal_to
50    {
51      _Type __value;
52
53    public:
54      explicit _Not_equal_to(const _Type& __v) : __value(__v) { }
55
56      bool
57      operator()(const _Type& __x) const
58      { return __value != __x; }
59    };
60
61  /** A function object that returns true when the given random access
62      iterator is at least @c n steps away from the given iterator. */
63  template<typename _Iterator>
64    class _After_nth_from
65    {
66      typedef typename std::iterator_traits<_Iterator>::difference_type
67      difference_type;
68
69      _Iterator _M_base;
70      difference_type _M_n;
71
72    public:
73      _After_nth_from(const difference_type& __n, const _Iterator& __base)
74      : _M_base(__base), _M_n(__n) { }
75
76      bool
77      operator()(const _Iterator& __x) const
78      { return __x - _M_base >= _M_n; }
79    };
80
81  /**
82   * @brief Base class for constructing a "safe" sequence type that
83   * tracks iterators that reference it.
84   *
85   * The class template %_Safe_sequence simplifies the construction of
86   * "safe" sequences that track the iterators that reference the
87   * sequence, so that the iterators are notified of changes in the
88   * sequence that may affect their operation, e.g., if the container
89   * invalidates its iterators or is destructed. This class template
90   * may only be used by deriving from it and passing the name of the
91   * derived class as its template parameter via the curiously
92   * recurring template pattern. The derived class must have @c
93   * iterator and @const_iterator types that are instantiations of
94   * class template _Safe_iterator for this sequence. Iterators will
95   * then be tracked automatically.
96   */
97  template<typename _Sequence>
98    class _Safe_sequence : public _Safe_sequence_base
99    {
100    public:
101      /** Invalidates all iterators @c x that reference this sequence,
102	  are not singular, and for which @c pred(x) returns @c
103	  true. The user of this routine should be careful not to make
104	  copies of the iterators passed to @p pred, as the copies may
105	  interfere with the invalidation. */
106      template<typename _Predicate>
107        void
108        _M_invalidate_if(_Predicate __pred);
109
110      /** Transfers all iterators that reference this memory location
111	  to this sequence from whatever sequence they are attached
112	  to. */
113      template<typename _Iterator>
114        void
115        _M_transfer_iter(const _Safe_iterator<_Iterator, _Sequence>& __x);
116    };
117
118  template<typename _Sequence>
119    template<typename _Predicate>
120      void
121      _Safe_sequence<_Sequence>::
122      _M_invalidate_if(_Predicate __pred)
123      {
124        typedef typename _Sequence::iterator iterator;
125        typedef typename _Sequence::const_iterator const_iterator;
126
127        for (_Safe_iterator_base* __iter = _M_iterators; __iter; )
128        {
129          iterator* __victim = static_cast<iterator*>(__iter);
130          __iter = __iter->_M_next;
131          if (!__victim->_M_singular())
132          {
133	    if (__pred(__victim->base()))
134	      __victim->_M_invalidate();
135          }
136        }
137
138        for (_Safe_iterator_base* __iter2 = _M_const_iterators; __iter2; )
139        {
140          const_iterator* __victim = static_cast<const_iterator*>(__iter2);
141          __iter2 = __iter2->_M_next;
142          if (!__victim->_M_singular())
143          {
144	    if (__pred(__victim->base()))
145	      __victim->_M_invalidate();
146          }
147        }
148      }
149
150  template<typename _Sequence>
151    template<typename _Iterator>
152      void
153      _Safe_sequence<_Sequence>::
154      _M_transfer_iter(const _Safe_iterator<_Iterator, _Sequence>& __x)
155      {
156	_Safe_sequence_base* __from = __x._M_sequence;
157	if (!__from)
158	  return;
159
160        typedef typename _Sequence::iterator iterator;
161        typedef typename _Sequence::const_iterator const_iterator;
162
163        for (_Safe_iterator_base* __iter = __from->_M_iterators; __iter; )
164        {
165          iterator* __victim = static_cast<iterator*>(__iter);
166          __iter = __iter->_M_next;
167          if (!__victim->_M_singular() && __victim->base() == __x.base())
168	    __victim->_M_attach(static_cast<_Sequence*>(this));
169        }
170
171        for (_Safe_iterator_base* __iter2 = __from->_M_const_iterators;
172	     __iter2;)
173        {
174          const_iterator* __victim = static_cast<const_iterator*>(__iter2);
175          __iter2 = __iter2->_M_next;
176          if (!__victim->_M_singular() && __victim->base() == __x.base())
177	    __victim->_M_attach(static_cast<_Sequence*>(this));
178        }
179      }
180} // namespace __gnu_debug
181
182#endif
183