template <typename _Base>

   class MappableUndirBipartiteGraphExtender : public _Base {

   public:

     typedef _Base Parent;

     typedef MappableUndirBipartiteGraphExtender Graph;

     typedef typename Parent::Node Node;

     typedef typename Parent::UpperNode UpperNode;

     typedef typename Parent::LowerNode LowerNode;

     typedef typename Parent::Edge Edge;

     typedef typename Parent::UndirEdge UndirEdge;

     template <typename _Value>

     class UpperNodeMap 

       : public IterableMapExtender<DefaultMap<Graph, UpperNode, _Value> > {

     public:

       typedef MappableUndirBipartiteGraphExtender Graph;

       typedef IterableMapExtender<DefaultMap<Graph, UpperNode, _Value> > 

       Parent;

       UpperNodeMap(const Graph& _g) 

 	: Parent(_g) {}

       UpperNodeMap(const Graph& _g, const _Value& _v) 

 	: Parent(_g, _v) {}

       UpperNodeMap& operator=(const UpperNodeMap& cmap) {

 	return operator=<UpperNodeMap>(cmap);

       }

       /// \brief Template assign operator.

       ///

       /// The given parameter should be conform to the ReadMap

       /// concept and could be indiced by the current item set of

       /// the UpperNodeMap. In this case the value for each item

       /// is assigned by the value of the given ReadMap. 

       template <typename CMap>

       UpperNodeMap& operator=(const CMap& cmap) {

 	checkConcept<concept::ReadMap<UpperNode, _Value>, CMap>();

 	const typename Parent::Graph* graph = Parent::getGraph();

 	UpperNode it;

 	for (graph->first(it); it != INVALID; graph->next(it)) {

 	  Parent::set(it, cmap[it]);

 	}

 	return *this;

       }

     };

     template <typename _Value>

     class LowerNodeMap 

       : public IterableMapExtender<DefaultMap<Graph, LowerNode, _Value> > {

     public:

       typedef MappableUndirBipartiteGraphExtender Graph;

       typedef IterableMapExtender<DefaultMap<Graph, LowerNode, _Value> > 

       Parent;

       LowerNodeMap(const Graph& _g) 

 	: Parent(_g) {}

       LowerNodeMap(const Graph& _g, const _Value& _v) 

 	: Parent(_g, _v) {}

       LowerNodeMap& operator=(const LowerNodeMap& cmap) {

 	return operator=<LowerNodeMap>(cmap);

       }

       /// \brief Template assign operator.

       ///

       /// The given parameter should be conform to the ReadMap

       /// concept and could be indiced by the current item set of

       /// the LowerNodeMap. In this case the value for each item

       /// is assigned by the value of the given ReadMap. 

       template <typename CMap>

       LowerNodeMap& operator=(const CMap& cmap) {

 	checkConcept<concept::ReadMap<LowerNode, _Value>, CMap>();

 	const typename Parent::Graph* graph = Parent::getGraph();

 	LowerNode it;

 	for (graph->first(it); it != INVALID; graph->next(it)) {

 	  Parent::set(it, cmap[it]);

 	}

 	return *this;

       }

     };

   protected:

     template <typename _Value>

     class NodeMapBase : public Parent::NodeNotifier::ObserverBase {

     public:

       typedef MappableUndirBipartiteGraphExtender Graph;

       typedef Node Key;

       typedef _Value Value;

       /// The reference type of the map;

       typedef typename LowerNodeMap<_Value>::Reference Reference;

       /// The pointer type of the map;

       typedef typename LowerNodeMap<_Value>::Pointer Pointer;

       /// The const value type of the map.

       typedef const Value ConstValue;

       /// The const reference type of the map;

       typedef typename LowerNodeMap<_Value>::ConstReference ConstReference;

       /// The pointer type of the map;

       typedef typename LowerNodeMap<_Value>::ConstPointer ConstPointer;

       typedef True ReferenceMapTag;

       NodeMapBase(const Graph& _g) 

 	: graph(&_g), lowerMap(_g), upperMap(_g) {

 	Parent::NodeNotifier::ObserverBase::attach(_g.getNotifier(Node()));

       }

       NodeMapBase(const Graph& _g, const _Value& _v) 

 	: graph(&_g), lowerMap(_g, _v), 

 	  upperMap(_g, _v) {

 	Parent::NodeNotifier::ObserverBase::attach(_g.getNotifier(Node()));

       }

       virtual ~NodeMapBase() {      

 	if (Parent::NodeNotifier::ObserverBase::attached()) {

 	  Parent::NodeNotifier::ObserverBase::detach();

 	}

       }

       ConstReference operator[](const Key& node) const {

 	if (Parent::upper(node)) {

 	  return upperMap[node];

 	} else {

 	  return lowerMap[node];

 	}

       } 

       Reference operator[](const Key& node) {

 	if (Parent::upper(node)) {

 	  return upperMap[node];

 	} else {

 	  return lowerMap[node];

 	}

       }

       void set(const Key& node, const Value& value) {

 	if (Parent::upper(node)) {

 	  upperMap.set(node, value);

 	} else {

 	  lowerMap.set(node, value);

 	}

       }

     protected:

       virtual void add(const Node&) {}

       virtual void erase(const Node&) {}

       virtual void clear() {}

       virtual void build() {}

       const Graph* getGraph() const { return graph; }

     private:

       const Graph* graph;

       LowerNodeMap<_Value> lowerMap;

       UpperNodeMap<_Value> upperMap;

     };

   public:

     template <typename _Value>

     class NodeMap 

       : public IterableMapExtender<NodeMapBase<_Value> > {

     public:

       typedef MappableUndirBipartiteGraphExtender Graph;

       typedef IterableMapExtender< NodeMapBase<_Value> > Parent;

       NodeMap(const Graph& _g) 

 	: Parent(_g) {}

       NodeMap(const Graph& _g, const _Value& _v) 

 	: Parent(_g, _v) {}

       NodeMap& operator=(const NodeMap& cmap) {

 	return operator=<NodeMap>(cmap);

       }

       /// \brief Template assign operator.

       ///

       /// The given parameter should be conform to the ReadMap

       /// concept and could be indiced by the current item set of

       /// the NodeMap. In this case the value for each item

       /// is assigned by the value of the given ReadMap. 

       template <typename CMap>

       NodeMap& operator=(const CMap& cmap) {

 	checkConcept<concept::ReadMap<Node, _Value>, CMap>();

 	const typename Parent::Graph* graph = Parent::getGraph();

 	Node it;

 	for (graph->first(it); it != INVALID; graph->next(it)) {

 	  Parent::set(it, cmap[it]);

 	}

 	return *this;

       }

     };

     template <typename _Value>

     class EdgeMap 

       : public IterableMapExtender<DefaultMap<Graph, Edge, _Value> > {

     public:

       typedef MappableUndirBipartiteGraphExtender Graph;

       typedef IterableMapExtender<DefaultMap<Graph, Edge, _Value> > Parent;

       EdgeMap(const Graph& _g) 

 	: Parent(_g) {}

       EdgeMap(const Graph& _g, const _Value& _v) 

 	: Parent(_g, _v) {}

       EdgeMap& operator=(const EdgeMap& cmap) {

 	return operator=<EdgeMap>(cmap);

       }

       template <typename CMap>

       EdgeMap& operator=(const CMap& cmap) {

 	checkConcept<concept::ReadMap<Edge, _Value>, CMap>();

 	const typename Parent::Graph* graph = Parent::getGraph();

 	Edge it;

 	for (graph->first(it); it != INVALID; graph->next(it)) {

 	  Parent::set(it, cmap[it]);

 	}

 	return *this;

       }

     };

     template <typename _Value>

     class UndirEdgeMap 

       : public IterableMapExtender<DefaultMap<Graph, UndirEdge, _Value> > {

     public:

       typedef MappableUndirBipartiteGraphExtender Graph;

       typedef IterableMapExtender<DefaultMap<Graph, UndirEdge, _Value> > 

       Parent;

       UndirEdgeMap(const Graph& _g) 

 	: Parent(_g) {}

       UndirEdgeMap(const Graph& _g, const _Value& _v) 

 	: Parent(_g, _v) {}

       UndirEdgeMap& operator=(const UndirEdgeMap& cmap) {

 	return operator=<UndirEdgeMap>(cmap);

       }

       template <typename CMap>

       UndirEdgeMap& operator=(const CMap& cmap) {

 	checkConcept<concept::ReadMap<UndirEdge, _Value>, CMap>();

 	const typename Parent::Graph* graph = Parent::getGraph();

 	UndirEdge it;

 	for (graph->first(it); it != INVALID; graph->next(it)) {

 	  Parent::set(it, cmap[it]);

 	}

 	return *this;

       }

     };

   };