libstdc++
safe_sequence.h
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1 // Safe sequence implementation -*- C++ -*-
2 
3 // Copyright (C) 2003-2015 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 debug/safe_sequence.h
26  * This file is a GNU debug extension to the Standard C++ Library.
27  */
28 
29 #ifndef _GLIBCXX_DEBUG_SAFE_SEQUENCE_H
30 #define _GLIBCXX_DEBUG_SAFE_SEQUENCE_H 1
31 
32 #include <debug/debug.h>
33 #include <debug/macros.h>
34 #include <debug/functions.h>
35 #include <debug/safe_base.h>
36 
37 namespace __gnu_debug
38 {
39  template<typename _Iterator, typename _Sequence>
40  class _Safe_iterator;
41 
42  /** A simple function object that returns true if the passed-in
43  * value is not equal to the stored value. It saves typing over
44  * using both bind1st and not_equal.
45  */
46  template<typename _Type>
48  {
49  _Type __value;
50 
51  public:
52  explicit _Not_equal_to(const _Type& __v) : __value(__v) { }
53 
54  bool
55  operator()(const _Type& __x) const
56  { return __value != __x; }
57  };
58 
59  /** A simple function object that returns true if the passed-in
60  * value is equal to the stored value. */
61  template <typename _Type>
62  class _Equal_to
63  {
64  _Type __value;
65 
66  public:
67  explicit _Equal_to(const _Type& __v) : __value(__v) { }
68 
69  bool
70  operator()(const _Type& __x) const
71  { return __value == __x; }
72  };
73 
74  /** A function object that returns true when the given random access
75  iterator is at least @c n steps away from the given iterator. */
76  template<typename _Iterator>
78  {
79  typedef typename std::iterator_traits<_Iterator>::difference_type
80  difference_type;
81 
82  _Iterator _M_base;
83  difference_type _M_n;
84 
85  public:
86  _After_nth_from(const difference_type& __n, const _Iterator& __base)
87  : _M_base(__base), _M_n(__n) { }
88 
89  bool
90  operator()(const _Iterator& __x) const
91  { return __x - _M_base >= _M_n; }
92  };
93 
94  /**
95  * @brief Base class for constructing a @a safe sequence type that
96  * tracks iterators that reference it.
97  *
98  * The class template %_Safe_sequence simplifies the construction of
99  * @a safe sequences that track the iterators that reference the
100  * sequence, so that the iterators are notified of changes in the
101  * sequence that may affect their operation, e.g., if the container
102  * invalidates its iterators or is destructed. This class template
103  * may only be used by deriving from it and passing the name of the
104  * derived class as its template parameter via the curiously
105  * recurring template pattern. The derived class must have @c
106  * iterator and @c const_iterator types that are instantiations of
107  * class template _Safe_iterator for this sequence. Iterators will
108  * then be tracked automatically.
109  */
110  template<typename _Sequence>
111  class _Safe_sequence : public _Safe_sequence_base
112  {
113  public:
114  /** Invalidates all iterators @c x that reference this sequence,
115  are not singular, and for which @c __pred(x) returns @c
116  true. @c __pred will be invoked with the normal iterators nested
117  in the safe ones. */
118  template<typename _Predicate>
119  void
120  _M_invalidate_if(_Predicate __pred);
121 
122  /** Transfers all iterators @c x that reference @c from sequence,
123  are not singular, and for which @c __pred(x) returns @c
124  true. @c __pred will be invoked with the normal iterators nested
125  in the safe ones. */
126  template<typename _Predicate>
127  void
128  _M_transfer_from_if(_Safe_sequence& __from, _Predicate __pred);
129  };
130 
131  /// Like _Safe_sequence but with a special _M_invalidate_all implementation
132  /// not invalidating past-the-end iterators. Used by node based sequence.
133  template<typename _Sequence>
135  : public _Safe_sequence<_Sequence>
136  {
137  protected:
138  void
139  _M_invalidate_all()
140  {
141  typedef typename _Sequence::const_iterator _Const_iterator;
142  typedef typename _Const_iterator::iterator_type _Base_const_iterator;
144  const _Sequence& __seq = *static_cast<_Sequence*>(this);
145  this->_M_invalidate_if(_Not_equal(__seq._M_base().end()));
146  }
147  };
148 
149 } // namespace __gnu_debug
150 
151 #include <debug/safe_sequence.tcc>
152 
153 #endif
Like _Safe_sequence but with a special _M_invalidate_all implementation not invalidating past-the-end...
Base class that supports tracking of iterators that reference a sequence.
Definition: safe_base.h:179
GNU debug classes for public use.
_Siter_base< _Iterator >::iterator_type __base(_Iterator __it)
Definition: functions.h:558
Base class for constructing a safe sequence type that tracks iterators that reference it...
Definition: formatter.h:52