1 // Safe sequence implementation  -*- C++ -*-
2 
3 // Copyright (C) 2003-2014 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>
47     class _Not_equal_to
48     {
49       _Type __value;
50 
51     public:
_Not_equal_to(const _Type & __v)52       explicit _Not_equal_to(const _Type& __v) : __value(__v) { }
53 
54       bool
operator()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:
_Equal_to(const _Type & __v)67       explicit _Equal_to(const _Type& __v) : __value(__v) { }
68 
69       bool
operator()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>
77     class _After_nth_from
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:
_After_nth_from(const difference_type & __n,const _Iterator & __base)86       _After_nth_from(const difference_type& __n, const _Iterator& __base)
87       : _M_base(__base), _M_n(__n) { }
88 
89       bool
operator()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 } // namespace __gnu_debug
131 
132 #include <debug/safe_sequence.tcc>
133 
134 #endif
135