// -*- c++ -*-

 #ifndef SYM_MAP_FACTORY_H

 #define SYM_MAP_FACTORY_H

 namespace hugo {

   template <typename Graph, typename Edge, typename EdgeIt>

   class SymEdgeIt : public EdgeIt {

   public:

     SymEdgeIt() 

       : EdgeIt() {}

     SymEdgeIt(const Graph& graph) 

       : EdgeIt(graph) {}

     SymEdgeIt(Invalid invalid) 

       : EdgeIt(invalid) {}

     SymEdgeIt(const Graph& graph, Edge edge)

       : EdgeIt(graph, edge) {}

     SymEdgeIt& operator++() {

       EdgeIt::operator++();

       while ( n != -1 && (n & 1)) {

 	EdgeIt::operator++();

       }

       return *this;

     }

   };

   template <typename MapRegistry, template <typename> class MapFactory>

   class SymMapFactory {

   public:

     typedef typename MapRegistry::Graph Graph;

     typedef typename MapRegistry::Key Key;

     typedef typename MapRegistry::KeyIt KeyIt;

     typedef typename MapRegistry::MapBase MapBase;

     template <typename V>

     class Map : public MapFactory<MapRegistry>::template Map<V> {

       typedef typename MapFactory<MapRegistry>::template Map<V> MapImpl;

     public:

       typedef V Value;

       Map() : MapImpl() {}

       Map(const Graph& g, MapRegistry& r) : MapImpl(g, r) {}

       Map(const Graph& g, MapRegistry& r, const Value& v) : MapImpl(g, r, v) {}

       Map(const Map& copy) : MapImpl(static_cast<const MapImpl&>(copy)) {}

       template <typename CMap> Map(const CMap& copy) : MapImpl(copy) {}

       Map& operator=(const Map& copy) {

 	MapImpl::operator=(static_cast<const MapImpl&>(copy));

 	return *this;

       }

       template <typename CMap> Map& operator=(const CMap& copy) {

 	MapImpl::operator=(copy);

 	return *this;

       }

       Value& operator[](const Key& key) {

 	int id = MapBase::getGraph()->id(key);	

 	return MapImpl::operator[](id >> 1);

       } 

       const Value& operator[](const Key& key) const {

 	int id = MapBase::getGraph()->id(key);

 	return MapImpl::operator[](id >> 1);

       }

       const Value& get(const Key& key) const {

 	int id = MapBase::getGraph()->id(key);

 	return MapImpl::operator[](id >> 1);

       } 

       void set(const Key& key, const Value& val) {

 	int id = MapBase::getGraph()->id(key);

 	MapImpl::operator[](id >> 1) = val;

       }

       void add(const Key& key) {

 	int id = MapBase::getGraph()->id(key);

 	if (id & 1) return;

 	MapImpl::add(key);

       }

       void erase(const Key& key) {

 	int id = MapBase::getGraph()->id(key);

 	if (id & 1) return;

 	MapImpl::add(key);

       }

     };  

   };

 }

 #endif