safe_sequence.h   [plain text]


/* APPLE LOCAL file libstdc++ debug mode */
// Safe sequence implementation  -*- C++ -*-

// Copyright (C) 2003
// Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

#ifndef _GLIBCXX_DEBUG_SAFE_SEQUENCE_H
#define _GLIBCXX_DEBUG_SAFE_SEQUENCE_H

#include <debug/debug.h>
#include <debug/safe_base.h>

namespace std
{
  namespace __debug
  {
    template<typename _Iterator, typename _Sequence> class _Safe_iterator;

    /** A simple function object that returns true if the passed-in
	value is not equal to the stored value. It saves typing over
	using both bind1st and not_equal. */
    template<typename _Type>
      class _Not_equal_to
      {
	_Type __value;
	
      public:
	explicit _Not_equal_to(const _Type& __v) : __value(__v) { }

	bool 
	operator()(const _Type& __x) const 
	{ return __value != __x; }
      };

    /** A function object that returns true when the given random access
	iterator is at least @c n steps away from the given iterator. */
    template<typename _Iterator>
      class _After_nth_from
      {
	typedef typename std::iterator_traits<_Iterator>::difference_type
          difference_type;

	_Iterator _M_base;
	difference_type _M_n;
	
      public:
	_After_nth_from(const difference_type& __n, const _Iterator& __base)
	: _M_base(__base), _M_n(__n) 
	{ }
	
	bool 
	operator()(const _Iterator& __x) const
	{ return __x - _M_base >= _M_n; }
      };
    
    /**
     * @brief Base class for constructing a "safe" sequence type that
     * tracks iterators that reference it.
     *
     * The class template %_Safe_sequence simplifies the construction
     * of "safe" sequences that track the iterators that reference the
     * sequence, so that the iterators are notified of changes in the
     * sequence that may affect their operation, e.g., if the
     * container invalidates its iterators or is destructed. This
     * class template may only be used by deriving from it and passing
     * the name of the derived class as its template parameter via the
     * curiously recurring template pattern. The derived class must
     * have @c iterator and @const_iterator types that are
     * instantiations of class template _Safe_iterator for this
     * sequence. Iterators will then be tracked automatically.
     */
  template<typename _Sequence>
    class _Safe_sequence : public _Safe_sequence_base
    {
    public:
      /** Invalidates all iterators @c x that reference this sequence,
	  are not singular, and for which @c pred(x) returns @c
	  true. The user of this routine should be careful not to make
	  copies of the iterators passed to @p pred, as the copies may
	  interfere with the invalidation. */
      template<typename _Predicate> 
        void 
        _M_invalidate_if(_Predicate __pred);

      /** Transfers all iterators that reference this memory location
	  to this sequence from whatever sequence they are attached
	  to. */
      template<typename _Iterator>
        void
        _M_transfer_iter(const _Safe_iterator<_Iterator, _Sequence>& __x);
    };

  template<typename _Sequence>
    template<typename _Predicate> 
      void 
      _Safe_sequence<_Sequence>::
      _M_invalidate_if(_Predicate __pred)
      {
        typedef typename _Sequence::iterator iterator;
        typedef typename _Sequence::const_iterator const_iterator;
        
        for (_Safe_iterator_base* __iter = _M_iterators; __iter; )
        {
          iterator* __victim = static_cast<iterator*>(__iter);
          __iter = __iter->_M_next;
          if (!__victim->_M_singular()) 
          {
	    if (__pred(__victim->base()))
	      __victim->_M_invalidate();
          }
        }

        for (_Safe_iterator_base* __iter = _M_const_iterators; __iter; )
        {
          const_iterator* __victim = static_cast<const_iterator*>(__iter);
          __iter = __iter->_M_next;
          if (!__victim->_M_singular()) 
          {
	    if (__pred(__victim->base()))
	      __victim->_M_invalidate();
          }
        }    
      }

  template<typename _Sequence>
    template<typename _Iterator>
      void
      _Safe_sequence<_Sequence>::
      _M_transfer_iter(const _Safe_iterator<_Iterator, _Sequence>& __x)
      {
	_Safe_sequence_base* __from = __x._M_sequence;
	if (!__from)
	  return;

        typedef typename _Sequence::iterator iterator;
        typedef typename _Sequence::const_iterator const_iterator;
        
        for (_Safe_iterator_base* __iter = __from->_M_iterators; __iter; )
        {
          iterator* __victim = static_cast<iterator*>(__iter);
          __iter = __iter->_M_next;
          if (!__victim->_M_singular() && __victim->base() == __x.base())
	    __victim->_M_attach(static_cast<_Sequence*>(this));
        }

        for (_Safe_iterator_base* __iter = __from->_M_const_iterators; __iter;)
        {
          const_iterator* __victim = static_cast<const_iterator*>(__iter);
          __iter = __iter->_M_next;
          if (!__victim->_M_singular() && __victim->base() == __x.base())
	    __victim->_M_attach(static_cast<_Sequence*>(this));
        }
      }
} // namespace std
} // namespace __debug

#endif /* _GLIBCXX_DEBUG_SAFE_SEQUENCE_H */