libstdc++-v3/include/debug/safe_sequence.h

   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, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  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
  39 namespace __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