/* -*-	Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */

/*

 * Copyright (c) 2006 INRIA

 * All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation;

 *

 * This program 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 program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

 */

#ifndef REFERENCE_LIST_H

#define REFERENCE_LIST_H

/* This is a reference list implementation. The technique underlying

 * this code was first described in 1995 by Risto Lankinen on Usenet

 * but I have never been able to find his original posting. Instead,

 * this code is based on the description of the technique found in

 * "Modern C++ design" by Andrei Alexandrescu in chapter 7.

 */

namespace ns3 {

template <typename OBJ_PTR>

class ReferenceList;

template <typename OBJ_PTR>

class ReferenceList {

public:

	ReferenceList () 

		   m_prev (), 

		   m_next () 

	{

		m_prev = this;

		m_next = this;

	}

	ReferenceList (ReferenceList &o) 

		  m_prev (), 

		  m_next ()

	{

		m_prev = this;

		m_next = this;

		insert_self_in_other (o);

	}

	ReferenceList (ReferenceList const&o) 

		  m_prev (), 

		  m_next ()

	{

		m_prev = this;

		m_next = this;

		insert_self_in_other (o);

	}

	ReferenceList (OBJ_PTR const &obj_ptr)

		  m_prev (), 

		  m_next ()

	{

		m_prev = this;

		m_next = this;

	}

	~ReferenceList () {

		remove_from_list ();

	}

	ReferenceList & operator= (ReferenceList const&o) {

		remove_from_list ();

		insert_self_in_other (o);

		return *this;

	}

	OBJ_PTR operator-> () {

	}

	void set (OBJ_PTR obj_ptr) {

		remove_from_list ();

	}

	OBJ_PTR get (void) {

		// explicit conversion to raw pointer type.

	}

private:

	void insert_self_in_other (ReferenceList const&o) {

		m_prev = &o;

		m_next = o.m_next;

		m_next->m_prev = this;

		o.m_next = this;

	}

	void remove_from_list (void) {

		if (m_prev == this) {

			//assert (m_next == this);

		}

		m_prev->m_next = m_next;

		m_next->m_prev = m_prev;

	}

	mutable ReferenceList const*m_prev;

	mutable ReferenceList const*m_next;

};

}; // namespace ns3

#endif /* REFERENCE_LIST_H */