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

   1 // Safe sequence implementation  -*- C++ -*-
   2
   3 // Copyright (C) 2003
   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/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:
  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 function object that returns true when the given random access
  60       iterator is at least @c n steps away from the given iterator. */
  61   template<typename _Iterator>
  62     class _After_nth_from
  63     {
  64       typedef typename std::iterator_traits<_Iterator>::difference_type
  65       difference_type;
  66
  67       _Iterator _M_base;
  68       difference_type _M_n;
  69
  70     public:
  71       _After_nth_from(const difference_type& __n, const _Iterator& __base)
  72       : _M_base(__base), _M_n(__n) { }
  73
  74       bool
  75       operator()(const _Iterator& __x) const
  76       { return __x - _M_base >= _M_n; }
  77     };
  78
  79   /**
  80    * @brief Base class for constructing a "safe" sequence type that
  81    * tracks iterators that reference it.
  82    *
  83    * The class template %_Safe_sequence simplifies the construction of
  84    * "safe" sequences that track the iterators that reference the
  85    * sequence, so that the iterators are notified of changes in the
  86    * sequence that may affect their operation, e.g., if the container
  87    * invalidates its iterators or is destructed. This class template
  88    * may only be used by deriving from it and passing the name of the
  89    * derived class as its template parameter via the curiously
  90    * recurring template pattern. The derived class must have @c
  91    * iterator and @const_iterator types that are instantiations of
  92    * class template _Safe_iterator for this sequence. Iterators will
  93    * then be tracked automatically.
  94    */
  95   template<typename _Sequence>
  96     class _Safe_sequence : public _Safe_sequence_base
  97     {
  98     public:
  99       /** Invalidates all iterators @c x that reference this sequence,
 100           are not singular, and for which @c pred(x) returns @c
 101           true. The user of this routine should be careful not to make
 102           copies of the iterators passed to @p pred, as the copies may
 103           interfere with the invalidation. */
 104       template<typename _Predicate>
 105         void
 106         _M_invalidate_if(_Predicate __pred);
 107
 108       /** Transfers all iterators that reference this memory location
 109           to this sequence from whatever sequence they are attached
 110           to. */
 111       template<typename _Iterator>
 112         void
 113         _M_transfer_iter(const _Safe_iterator<_Iterator, _Sequence>& __x);
 114     };
 115
 116   template<typename _Sequence>
 117     template<typename _Predicate>
 118       void
 119       _Safe_sequence<_Sequence>::
 120       _M_invalidate_if(_Predicate __pred)
 121       {
 122         typedef typename _Sequence::iterator iterator;
 123         typedef typename _Sequence::const_iterator const_iterator;
 124
 125         for (_Safe_iterator_base* __iter = _M_iterators; __iter; )
 126         {
 127           iterator* __victim = static_cast<iterator*>(__iter);
 128           __iter = __iter->_M_next;
 129           if (!__victim->_M_singular())
 130           {
 131             if (__pred(__victim->base()))
 132               __victim->_M_invalidate();
 133           }
 134         }
 135
 136         for (_Safe_iterator_base* __iter = _M_const_iterators; __iter; )
 137         {
 138           const_iterator* __victim = static_cast<const_iterator*>(__iter);
 139           __iter = __iter->_M_next;
 140           if (!__victim->_M_singular())
 141           {
 142             if (__pred(__victim->base()))
 143               __victim->_M_invalidate();
 144           }
 145         }
 146       }
 147
 148   template<typename _Sequence>
 149     template<typename _Iterator>
 150       void
 151       _Safe_sequence<_Sequence>::
 152       _M_transfer_iter(const _Safe_iterator<_Iterator, _Sequence>& __x)
 153       {
 154         _Safe_sequence_base* __from = __x._M_sequence;
 155         if (!__from)
 156           return;
 157
 158         typedef typename _Sequence::iterator iterator;
 159         typedef typename _Sequence::const_iterator const_iterator;
 160
 161         for (_Safe_iterator_base* __iter = __from->_M_iterators; __iter; )
 162         {
 163           iterator* __victim = static_cast<iterator*>(__iter);
 164           __iter = __iter->_M_next;
 165           if (!__victim->_M_singular() && __victim->base() == __x.base())
 166             __victim->_M_attach(static_cast<_Sequence*>(this));
 167         }
 168
 169         for (_Safe_iterator_base* __iter = __from->_M_const_iterators; __iter;)
 170         {
 171           const_iterator* __victim = static_cast<const_iterator*>(__iter);
 172           __iter = __iter->_M_next;
 173           if (!__victim->_M_singular() && __victim->base() == __x.base())
 174             __victim->_M_attach(static_cast<_Sequence*>(this));
 175         }
 176       }
 177 } // namespace __gnu_debug
 178
 179 #endif