/// }

   /// }

   ///\endcode

   ///\endcode

   /// 

   /// 

   ///\sa findEdge()

   ///\sa findEdge()

   ///\sa EdgeLookUp

   ///\sa EdgeLookUp

   ///

   ///

   /// \author Balazs Dezso 

   /// \author Balazs Dezso 

   template <typename _Graph>

   template <typename _Graph>

   class ConEdgeIt : public _Graph::Edge {

   class ConEdgeIt : public _Graph::Edge {

   public:

   public:

     ///Find an edge between two nodes.

     ///Find an edge between two nodes.

     ///\param s The source node

     ///\param s The source node

     ///\param t The target node

     ///\param t The target node

     ///\param prev The previous edge between \c s and \c t. It it is INVALID or

     ///\param prev The previous edge between \c s and \c t. It it is INVALID or

     ///not given, the operator finds the first appropriate edge.

     ///not given, the operator finds the first appropriate edge.

     ///\ref INVALID if there is no more.

     ///\ref INVALID if there is no more.

     ///

     ///

     ///For example, you can count the number of edges from \c u to \c v in the

     ///For example, you can count the number of edges from \c u to \c v in the

     ///following way.

     ///following way.

     ///\code

     ///\code