# safe_sequence.h

    00001 // Safe sequence implementation  -*- C++ -*-
    00002
    00003 // Copyright (C) 2003, 2004
    00004 // Free Software Foundation, Inc.
    00005 //
    00006 // This file is part of the GNU ISO C++ Library.  This library is free
    00007 // software; you can redistribute it and/or modify it under the
    00008 // terms of the GNU General Public License as published by the
    00009 // Free Software Foundation; either version 2, or (at your option)
    00010 // any later version.
    00011
    00012 // This library is distributed in the hope that it will be useful,
    00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00015 // GNU General Public License for more details.
    00016
    00017 // You should have received a copy of the GNU General Public License along
    00018 // with this library; see the file COPYING.  If not, write to the Free
    00019 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
    00020 // USA.
    00021
    00022 // As a special exception, you may use this file as part of a free software
    00023 // library without restriction.  Specifically, if other files instantiate
    00024 // templates or use macros or inline functions from this file, or you compile
    00025 // this file and link it with other files to produce an executable, this
    00026 // file does not by itself cause the resulting executable to be covered by
    00027 // the GNU General Public License.  This exception does not however
    00028 // invalidate any other reasons why the executable file might be covered by
    00029 // the GNU General Public License.
    00030
    00031 #ifndef _GLIBCXX_DEBUG_SAFE_SEQUENCE_H
    00032 #define _GLIBCXX_DEBUG_SAFE_SEQUENCE_H 1
    00033
    00034 #include <debug/debug.h>
    00035 #include <debug/safe_base.h>
    00036
    00037 namespace __gnu_debug
    00038 {
    00039   template<typename _Iterator, typename _Sequence>
    00040     class _Safe_iterator;
    00041
    00042   /** A simple function object that returns true if the passed-in
    00043    *  value is not equal to the stored value. It saves typing over
    00044    *  using both bind1st and not_equal.
    00045    */
    00046   template<typename _Type>
    00047     class _Not_equal_to
    00048     {
    00049       _Type __value;
    00050
    00051     public:
    00052       explicit _Not_equal_to(const _Type& __v) : __value(__v) { }
    00053
    00054       bool
    00055       operator()(const _Type& __x) const
    00056       { return __value != __x; }
    00057     };
    00058
    00059   /** A function object that returns true when the given random access
    00060       iterator is at least @c n steps away from the given iterator. */
    00061   template<typename _Iterator>
    00062     class _After_nth_from
    00063     {
    00064       typedef typename std::iterator_traits<_Iterator>::difference_type
    00065       difference_type;
    00066
    00067       _Iterator _M_base;
    00068       difference_type _M_n;
    00069
    00070     public:
    00071       _After_nth_from(const difference_type& __n, const _Iterator& __base)
    00072       : _M_base(__base), _M_n(__n) { }
    00073
    00074       bool
    00075       operator()(const _Iterator& __x) const
    00076       { return __x - _M_base >= _M_n; }
    00077     };
    00078
    00079   /**
    00080    * @brief Base class for constructing a "safe" sequence type that
    00081    * tracks iterators that reference it.
    00082    *
    00083    * The class template %_Safe_sequence simplifies the construction of
    00084    * "safe" sequences that track the iterators that reference the
    00085    * sequence, so that the iterators are notified of changes in the
    00086    * sequence that may affect their operation, e.g., if the container
    00087    * invalidates its iterators or is destructed. This class template
    00088    * may only be used by deriving from it and passing the name of the
    00089    * derived class as its template parameter via the curiously
    00090    * recurring template pattern. The derived class must have @c
    00091    * iterator and @const_iterator types that are instantiations of
    00092    * class template _Safe_iterator for this sequence. Iterators will
    00093    * then be tracked automatically.
    00094    */
    00095   template<typename _Sequence>
    00096     class _Safe_sequence : public _Safe_sequence_base
    00097     {
    00098     public:
    00099       /** Invalidates all iterators @c x that reference this sequence,
    00100       are not singular, and for which @c pred(x) returns @c
    00101       true. The user of this routine should be careful not to make
    00102       copies of the iterators passed to @p pred, as the copies may
    00103       interfere with the invalidation. */
    00104       template<typename _Predicate>
    00105         void
    00106         _M_invalidate_if(_Predicate __pred);
    00107
    00108       /** Transfers all iterators that reference this memory location
    00109       to this sequence from whatever sequence they are attached
    00110       to. */
    00111       template<typename _Iterator>
    00112         void
    00113         _M_transfer_iter(const _Safe_iterator<_Iterator, _Sequence>& __x);
    00114     };
    00115
    00116   template<typename _Sequence>
    00117     template<typename _Predicate>
    00118       void
    00119       _Safe_sequence<_Sequence>::
    00120       _M_invalidate_if(_Predicate __pred)
    00121       {
    00122         typedef typename _Sequence::iterator iterator;
    00123         typedef typename _Sequence::const_iterator const_iterator;
    00124
    00125         for (_Safe_iterator_base* __iter = _M_iterators; __iter; )
    00126         {
    00127           iterator* __victim = static_cast<iterator*>(__iter);
    00128           __iter = __iter->_M_next;
    00129           if (!__victim->_M_singular())
    00130           {
    00131         if (__pred(__victim->base()))
    00132           __victim->_M_invalidate();
    00133           }
    00134         }
    00135
    00136         for (_Safe_iterator_base* __iter2 = _M_const_iterators; __iter2; )
    00137         {
    00138           const_iterator* __victim = static_cast<const_iterator*>(__iter2);
    00139           __iter2 = __iter2->_M_next;
    00140           if (!__victim->_M_singular())
    00141           {
    00142         if (__pred(__victim->base()))
    00143           __victim->_M_invalidate();
    00144           }
    00145         }
    00146       }
    00147
    00148   template<typename _Sequence>
    00149     template<typename _Iterator>
    00150       void
    00151       _Safe_sequence<_Sequence>::
    00152       _M_transfer_iter(const _Safe_iterator<_Iterator, _Sequence>& __x)
    00153       {
    00154     _Safe_sequence_base* __from = __x._M_sequence;
    00155     if (!__from)
    00156       return;
    00157
    00158         typedef typename _Sequence::iterator iterator;
    00159         typedef typename _Sequence::const_iterator const_iterator;
    00160
    00161         for (_Safe_iterator_base* __iter = __from->_M_iterators; __iter; )
    00162         {
    00163           iterator* __victim = static_cast<iterator*>(__iter);
    00164           __iter = __iter->_M_next;
    00165           if (!__victim->_M_singular() && __victim->base() == __x.base())
    00166         __victim->_M_attach(static_cast<_Sequence*>(this));
    00167         }
    00168
    00169         for (_Safe_iterator_base* __iter2 = __from->_M_const_iterators;
    00170          __iter2;)
    00171         {
    00172           const_iterator* __victim = static_cast<const_iterator*>(__iter2);
    00173           __iter2 = __iter2->_M_next;
    00174           if (!__victim->_M_singular() && __victim->base() == __x.base())
    00175         __victim->_M_attach(static_cast<_Sequence*>(this));
    00176         }
    00177       }
    00178 } // namespace __gnu_debug
    00179
    00180 #endif