libstdc++
safe_sequence.h
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1 // Safe sequence implementation -*- C++ -*-
2 
3 // Copyright (C) 2003-2021 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/assertions.h>
33 #include <debug/macros.h>
34 #include <debug/functions.h>
35 #include <debug/safe_base.h>
36 
37 namespace __gnu_debug
38 {
39  /** A simple function object that returns true if the passed-in
40  * value is not equal to the stored value. It saves typing over
41  * using both bind1st and not_equal.
42  */
43  template<typename _Type>
45  {
46  _Type __value;
47 
48  public:
49  explicit _Not_equal_to(const _Type& __v) : __value(__v) { }
50 
51  bool
52  operator()(const _Type& __x) const
53  { return __value != __x; }
54  };
55 
56  /** A simple function object that returns true if the passed-in
57  * value is equal to the stored value. */
58  template <typename _Type>
59  class _Equal_to
60  {
61  _Type __value;
62 
63  public:
64  explicit _Equal_to(const _Type& __v) : __value(__v) { }
65 
66  bool
67  operator()(const _Type& __x) const
68  { return __value == __x; }
69  };
70 
71  /** A function object that returns true when the given random access
72  iterator is at least @c n steps away from the given iterator. */
73  template<typename _Iterator>
75  {
77  difference_type;
78 
79  _Iterator _M_base;
80  difference_type _M_n;
81 
82  public:
83  _After_nth_from(const difference_type& __n, const _Iterator& __base)
84  : _M_base(__base), _M_n(__n) { }
85 
86  bool
87  operator()(const _Iterator& __x) const
88  { return __x - _M_base >= _M_n; }
89  };
90 
91  /**
92  * @brief Base class for constructing a @a safe sequence type that
93  * tracks iterators that reference it.
94  *
95  * The class template %_Safe_sequence simplifies the construction of
96  * @a safe sequences that track the iterators that reference the
97  * sequence, so that the iterators are notified of changes in the
98  * sequence that may affect their operation, e.g., if the container
99  * invalidates its iterators or is destructed. This class template
100  * may only be used by deriving from it and passing the name of the
101  * derived class as its template parameter via the curiously
102  * recurring template pattern. The derived class must have @c
103  * iterator and @c const_iterator types that are instantiations of
104  * class template _Safe_iterator for this sequence. Iterators will
105  * then be tracked automatically.
106  */
107  template<typename _Sequence>
109  {
110  public:
111  /** Invalidates all iterators @c x that reference this sequence,
112  are not singular, and for which @c __pred(x) returns @c
113  true. @c __pred will be invoked with the normal iterators nested
114  in the safe ones. */
115  template<typename _Predicate>
116  void
117  _M_invalidate_if(_Predicate __pred);
118 
119  /** Transfers all iterators @c x that reference @c from sequence,
120  are not singular, and for which @c __pred(x) returns @c
121  true. @c __pred will be invoked with the normal iterators nested
122  in the safe ones. */
123  template<typename _Predicate>
124  void
125  _M_transfer_from_if(_Safe_sequence& __from, _Predicate __pred);
126  };
127 
128  /// Like _Safe_sequence but with a special _M_invalidate_all implementation
129  /// not invalidating past-the-end iterators. Used by node based sequence.
130  template<typename _Sequence>
132  : public _Safe_sequence<_Sequence>
133  {
134  protected:
135  void
136  _M_invalidate_all()
137  {
138  typedef typename _Sequence::const_iterator _Const_iterator;
139  typedef typename _Const_iterator::iterator_type _Base_const_iterator;
141  const _Sequence& __seq = *static_cast<_Sequence*>(this);
142  this->_M_invalidate_if(_Not_equal(__seq._M_base().end()));
143  }
144  };
145 
146 } // namespace __gnu_debug
147 
148 #include <debug/safe_sequence.tcc>
149 
150 #endif
GNU debug classes for public use.
constexpr _Iterator __base(_Iterator __it)
Traits class for iterators.
Base class for constructing a safe sequence type that tracks iterators that reference it.
void _M_invalidate_if(_Predicate __pred)
void _M_transfer_from_if(_Safe_sequence &__from, _Predicate __pred)
Base class that supports tracking of iterators that reference a sequence.
Definition: safe_base.h:189
Like _Safe_sequence but with a special _M_invalidate_all implementation not invalidating past-the-end...