klao@959: /* -*- C++ -*-
ladanyi@1435:  * lemon/concept/graph.h - Part of LEMON, a generic C++ optimization library
klao@959:  *
alpar@1164:  * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
alpar@1359:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
klao@959:  *
klao@959:  * Permission to use, modify and distribute this software is granted
klao@959:  * provided that this copyright notice appears in all copies. For
klao@959:  * precise terms see the accompanying LICENSE file.
klao@959:  *
klao@959:  * This software is provided "AS IS" with no warranty of any kind,
klao@959:  * express or implied, and with no claim as to its suitability for any
klao@959:  * purpose.
klao@959:  *
klao@959:  */
klao@959: 
klao@959: #ifndef LEMON_CONCEPT_SYM_GRAPH_H
klao@959: #define LEMON_CONCEPT_SYM_GRAPH_H
klao@959: 
klao@959: ///\ingroup concept
klao@959: ///\file
klao@959: ///\brief Declaration of SymGraph.
klao@959: 
klao@959: #include <lemon/invalid.h>
klao@959: #include <lemon/concept/graph.h>
klao@959: #include <lemon/concept/maps.h>
klao@959: 
klao@959: namespace lemon {
klao@959:   namespace concept {
klao@959:     
klao@959:     /// \addtogroup concept
klao@959:     /// @{
klao@959: 
klao@959:     /// An empty static graph class.
klao@959:   
klao@959:     /// This class provides all the common features of a symmetric
klao@959:     /// graph structure, however completely without implementations and 
klao@959:     /// real data structures behind the interface.
klao@959:     /// All graph algorithms should compile with this class, but it will not
klao@959:     /// run properly, of course.
klao@959:     ///
klao@959:     /// It can be used for checking the interface compatibility,
klao@959:     /// or it can serve as a skeleton of a new symmetric graph structure.
klao@959:     /// 
klao@959:     /// Also, you will find here the full documentation of a certain graph
klao@959:     /// feature, the documentation of a real symmetric graph imlementation
klao@959:     /// like @ref SymListGraph or
klao@959:     /// @ref lemon::SymSmartGraph will just refer to this structure.
klao@959:     class StaticSymGraph
klao@959:     {
klao@959:     public:
klao@959:       /// Defalult constructor.
klao@959: 
klao@959:       /// Defalult constructor.
klao@959:       ///
klao@959:       StaticSymGraph() { }
klao@959:       ///Copy consructor.
klao@959: 
klao@959: //       ///\todo It is not clear, what we expect from a copy constructor.
klao@959: //       ///E.g. How to assign the nodes/edges to each other? What about maps?
klao@959: //       StaticGraph(const StaticGraph& g) { }
klao@959: 
klao@959:       /// The base type of node iterators, 
klao@959:       /// or in other words, the trivial node iterator.
klao@959: 
klao@959:       /// This is the base type of each node iterator,
klao@959:       /// thus each kind of node iterator converts to this.
klao@959:       /// More precisely each kind of node iterator should be inherited 
klao@959:       /// from the trivial node iterator.
klao@959:       class Node {
klao@959:       public:
klao@959: 	/// Default constructor
klao@959: 
klao@959: 	/// @warning The default constructor sets the iterator
klao@959: 	/// to an undefined value.
klao@959: 	Node() { }
klao@959: 	/// Copy constructor.
klao@959: 
klao@959: 	/// Copy constructor.
klao@959: 	///
klao@959: 	Node(const Node&) { }
klao@959: 
klao@959: 	/// Invalid constructor \& conversion.
klao@959: 
klao@959: 	/// This constructor initializes the iterator to be invalid.
klao@959: 	/// \sa Invalid for more details.
klao@959: 	Node(Invalid) { }
klao@959: 	/// Equality operator
klao@959: 
klao@959: 	/// Two iterators are equal if and only if they point to the
klao@959: 	/// same object or both are invalid.
klao@959: 	bool operator==(Node) const { return true; }
klao@959: 
klao@959: 	/// Inequality operator
klao@959: 	
klao@959: 	/// \sa operator==(Node n)
klao@959: 	///
klao@959: 	bool operator!=(Node) const { return true; }
klao@959: 
klao@959:  	///Comparison operator.
klao@959: 
klao@959: 	///This is a strict ordering between the nodes.
klao@959: 	///
klao@959: 	///This ordering can be different from the order in which NodeIt
klao@959: 	///goes through the nodes.
klao@959: 	///\todo Possibly we don't need it.
klao@959: 	bool operator<(Node) const { return true; }
klao@959:       };
klao@959:     
klao@959:       /// This iterator goes through each node.
klao@959: 
klao@959:       /// This iterator goes through each node.
klao@959:       /// Its usage is quite simple, for example you can count the number
klao@959:       /// of nodes in graph \c g of type \c Graph like this:
klao@959:       /// \code
klao@959:       /// int count=0;
klao@959:       /// for (Graph::NodeIt n(g); n!=INVALID; ++n) ++count;
klao@959:       /// \endcode
klao@959:       class NodeIt : public Node {
klao@959:       public:
klao@959: 	/// Default constructor
klao@959: 
klao@959: 	/// @warning The default constructor sets the iterator
klao@959: 	/// to an undefined value.
klao@959: 	NodeIt() { }
klao@959: 	/// Copy constructor.
klao@959: 	
klao@959: 	/// Copy constructor.
klao@959: 	///
klao@959: 	NodeIt(const NodeIt&) { }
klao@959: 	/// Invalid constructor \& conversion.
klao@959: 
klao@959: 	/// Initialize the iterator to be invalid.
klao@959: 	/// \sa Invalid for more details.
klao@959: 	NodeIt(Invalid) { }
klao@959: 	/// Sets the iterator to the first node.
klao@959: 
klao@959: 	/// Sets the iterator to the first node of \c g.
klao@959: 	///
klao@959: 	NodeIt(const StaticSymGraph& g) { }
klao@959: 	/// Node -> NodeIt conversion.
klao@959: 
klao@959: 	/// Sets the iterator to the node of \c g pointed by the trivial 
klao@959: 	/// iterator n.
klao@959: 	/// This feature necessitates that each time we 
klao@959: 	/// iterate the edge-set, the iteration order is the same.
klao@959: 	NodeIt(const StaticSymGraph& g, const Node& n) { }
klao@959: 	/// Next node.
klao@959: 
klao@959: 	/// Assign the iterator to the next node.
klao@959: 	///
klao@959: 	NodeIt& operator++() { return *this; }
klao@959:       };
klao@959:     
klao@959:     
klao@959:       /// The base type of the symmetric edge iterators.
klao@959: 
klao@959:       /// The base type of the symmetric edge iterators.
klao@959:       ///
klao@959:       class SymEdge {
klao@959:       public:
klao@959: 	/// Default constructor
klao@959: 
klao@959: 	/// @warning The default constructor sets the iterator
klao@959: 	/// to an undefined value.
klao@959: 	SymEdge() { }
klao@959: 	/// Copy constructor.
klao@959: 
klao@959: 	/// Copy constructor.
klao@959: 	///
klao@959: 	SymEdge(const SymEdge&) { }
klao@959: 	/// Initialize the iterator to be invalid.
klao@959: 
klao@959: 	/// Initialize the iterator to be invalid.
klao@959: 	///
klao@959: 	SymEdge(Invalid) { }
klao@959: 	/// Equality operator
klao@959: 
klao@959: 	/// Two iterators are equal if and only if they point to the
klao@959: 	/// same object or both are invalid.
klao@959: 	bool operator==(SymEdge) const { return true; }
klao@959: 	/// Inequality operator
klao@959: 
klao@959: 	/// \sa operator==(Node n)
klao@959: 	///
klao@959: 	bool operator!=(SymEdge) const { return true; }
klao@959:  	///Comparison operator.
klao@959: 
klao@959: 	///This is a strict ordering between the nodes.
klao@959: 	///
klao@959: 	///This ordering can be different from the order in which NodeIt
klao@959: 	///goes through the nodes.
klao@959: 	///\todo Possibly we don't need it.
klao@959:  	bool operator<(SymEdge) const { return true; }
klao@959:       };
klao@959: 
klao@959: 
klao@959:       /// The base type of the edge iterators.
klao@959: 
klao@959:       /// The base type of the edge iterators.
klao@959:       ///
klao@959:       class Edge : public SymEdge {
klao@959:       public:
klao@959: 	/// Default constructor
klao@959: 
klao@959: 	/// @warning The default constructor sets the iterator
klao@959: 	/// to an undefined value.
klao@959: 	Edge() { }
klao@959: 	/// Copy constructor.
klao@959: 
klao@959: 	/// Copy constructor.
klao@959: 	///
klao@959: 	Edge(const Edge&) { }
klao@959: 	/// Initialize the iterator to be invalid.
klao@959: 
klao@959: 	/// Initialize the iterator to be invalid.
klao@959: 	///
klao@959: 	Edge(Invalid) { }
klao@959: 	/// Equality operator
klao@959: 
klao@959: 	/// Two iterators are equal if and only if they point to the
klao@959: 	/// same object or both are invalid.
klao@959: 	bool operator==(Edge) const { return true; }
klao@959: 	/// Inequality operator
klao@959: 
klao@959: 	/// \sa operator==(Node n)
klao@959: 	///
klao@959: 	bool operator!=(Edge) const { return true; }
klao@959:  	///Comparison operator.
klao@959: 
klao@959: 	///This is a strict ordering between the nodes.
klao@959: 	///
klao@959: 	///This ordering can be different from the order in which NodeIt
klao@959: 	///goes through the nodes.
klao@959: 	///\todo Possibly we don't need it.
klao@959:  	bool operator<(Edge) const { return true; }
klao@959:       };
klao@959:     
klao@959:       /// This iterator goes trough the outgoing edges of a node.
klao@959: 
klao@959:       /// This iterator goes trough the \e outgoing edges of a certain node
klao@959:       /// of a graph.
klao@959:       /// Its usage is quite simple, for example you can count the number
klao@959:       /// of outgoing edges of a node \c n
klao@959:       /// in graph \c g of type \c Graph as follows.
klao@959:       /// \code
klao@959:       /// int count=0;
klao@959:       /// for (Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) ++count;
klao@959:       /// \endcode
klao@959:     
klao@959:       class OutEdgeIt : public Edge {
klao@959:       public:
klao@959: 	/// Default constructor
klao@959: 
klao@959: 	/// @warning The default constructor sets the iterator
klao@959: 	/// to an undefined value.
klao@959: 	OutEdgeIt() { }
klao@959: 	/// Copy constructor.
klao@959: 
klao@959: 	/// Copy constructor.
klao@959: 	///
klao@959: 	OutEdgeIt(const OutEdgeIt&) { }
klao@959: 	/// Initialize the iterator to be invalid.
klao@959: 
klao@959: 	/// Initialize the iterator to be invalid.
klao@959: 	///
klao@959: 	OutEdgeIt(Invalid) { }
klao@959: 	/// This constructor sets the iterator to first outgoing edge.
klao@959:     
klao@959: 	/// This constructor set the iterator to the first outgoing edge of
klao@959: 	/// node
klao@959: 	///@param n the node
klao@959: 	///@param g the graph
klao@959: 	OutEdgeIt(const StaticSymGraph& g, const Node& n) { }
klao@959: 	/// Edge -> OutEdgeIt conversion
klao@959: 
klao@959: 	/// Sets the iterator to the value of the trivial iterator \c e.
klao@959: 	/// This feature necessitates that each time we 
klao@959: 	/// iterate the edge-set, the iteration order is the same.
klao@959: 	OutEdgeIt(const StaticSymGraph& g, const Edge& e) { }
klao@959: 	///Next outgoing edge
klao@959: 	
klao@959: 	/// Assign the iterator to the next 
klao@959: 	/// outgoing edge of the corresponding node.
klao@959: 	OutEdgeIt& operator++() { return *this; }
klao@959:       };
klao@959: 
klao@959:       /// This iterator goes trough the incoming edges of a node.
klao@959: 
klao@959:       /// This iterator goes trough the \e incoming edges of a certain node
klao@959:       /// of a graph.
klao@959:       /// Its usage is quite simple, for example you can count the number
klao@959:       /// of outgoing edges of a node \c n
klao@959:       /// in graph \c g of type \c Graph as follows.
klao@959:       /// \code
klao@959:       /// int count=0;
klao@959:       /// for(Graph::InEdgeIt e(g, n); e!=INVALID; ++e) ++count;
klao@959:       /// \endcode
klao@959: 
klao@959:       class InEdgeIt : public Edge {
klao@959:       public:
klao@959: 	/// Default constructor
klao@959: 
klao@959: 	/// @warning The default constructor sets the iterator
klao@959: 	/// to an undefined value.
klao@959: 	InEdgeIt() { }
klao@959: 	/// Copy constructor.
klao@959: 
klao@959: 	/// Copy constructor.
klao@959: 	///
klao@959: 	InEdgeIt(const InEdgeIt&) { }
klao@959: 	/// Initialize the iterator to be invalid.
klao@959: 
klao@959: 	/// Initialize the iterator to be invalid.
klao@959: 	///
klao@959: 	InEdgeIt(Invalid) { }
klao@959: 	/// This constructor sets the iterator to first incoming edge.
klao@959:     
klao@959: 	/// This constructor set the iterator to the first incoming edge of
klao@959: 	/// node
klao@959: 	///@param n the node
klao@959: 	///@param g the graph
klao@959: 	InEdgeIt(const StaticSymGraph& g, const Node& n) { }
klao@959: 	/// Edge -> InEdgeIt conversion
klao@959: 
klao@959: 	/// Sets the iterator to the value of the trivial iterator \c e.
klao@959: 	/// This feature necessitates that each time we 
klao@959: 	/// iterate the edge-set, the iteration order is the same.
klao@959: 	InEdgeIt(const StaticSymGraph& g, const Edge& n) { }
klao@959: 	/// Next incoming edge
klao@959: 
klao@959: 	/// Assign the iterator to the next inedge of the corresponding node.
klao@959: 	///
klao@959: 	InEdgeIt& operator++() { return *this; }
klao@959:       };
klao@959:       /// This iterator goes through each symmetric edge.
klao@959: 
klao@959:       /// This iterator goes through each symmetric edge of a graph.
klao@959:       /// Its usage is quite simple, for example you can count the number
klao@959:       /// of symmetric edges in a graph \c g of type \c Graph as follows:
klao@959:       /// \code
klao@959:       /// int count=0;
klao@959:       /// for(Graph::SymEdgeIt e(g); e!=INVALID; ++e) ++count;
klao@959:       /// \endcode
klao@959:       class SymEdgeIt : public SymEdge {
klao@959:       public:
klao@959: 	/// Default constructor
klao@959: 
klao@959: 	/// @warning The default constructor sets the iterator
klao@959: 	/// to an undefined value.
klao@959: 	SymEdgeIt() { }
klao@959: 	/// Copy constructor.
klao@959: 
klao@959: 	/// Copy constructor.
klao@959: 	///
klao@959: 	SymEdgeIt(const SymEdgeIt&) { }
klao@959: 	/// Initialize the iterator to be invalid.
klao@959: 
klao@959: 	/// Initialize the iterator to be invalid.
klao@959: 	///
klao@959: 	SymEdgeIt(Invalid) { }
klao@959: 	/// This constructor sets the iterator to first edge.
klao@959:     
klao@959: 	/// This constructor set the iterator to the first edge of
klao@959: 	/// node
klao@959: 	///@param g the graph
klao@959: 	SymEdgeIt(const StaticSymGraph& g) { }
klao@959: 	/// Edge -> EdgeIt conversion
klao@959: 
klao@959: 	/// Sets the iterator to the value of the trivial iterator \c e.
klao@959: 	/// This feature necessitates that each time we 
klao@959: 	/// iterate the edge-set, the iteration order is the same.
klao@959: 	SymEdgeIt(const StaticSymGraph&, const SymEdge&) { } 
klao@959:     	///Next edge
klao@959: 	
klao@959: 	/// Assign the iterator to the next 
klao@959: 	/// edge of the corresponding node.
klao@959: 	SymEdgeIt& operator++() { return *this; }
klao@959:       };
klao@959:       /// This iterator goes through each edge.
klao@959: 
klao@959:       /// This iterator goes through each edge of a graph.
klao@959:       /// Its usage is quite simple, for example you can count the number
klao@959:       /// of edges in a graph \c g of type \c Graph as follows:
klao@959:       /// \code
klao@959:       /// int count=0;
klao@959:       /// for(Graph::EdgeIt e(g); e!=INVALID; ++e) ++count;
klao@959:       /// \endcode
klao@959:       class EdgeIt : public Edge {
klao@959:       public:
klao@959: 	/// Default constructor
klao@959: 
klao@959: 	/// @warning The default constructor sets the iterator
klao@959: 	/// to an undefined value.
klao@959: 	EdgeIt() { }
klao@959: 	/// Copy constructor.
klao@959: 
klao@959: 	/// Copy constructor.
klao@959: 	///
klao@959: 	EdgeIt(const EdgeIt&) { }
klao@959: 	/// Initialize the iterator to be invalid.
klao@959: 
klao@959: 	/// Initialize the iterator to be invalid.
klao@959: 	///
klao@959: 	EdgeIt(Invalid) { }
klao@959: 	/// This constructor sets the iterator to first edge.
klao@959:     
klao@959: 	/// This constructor set the iterator to the first edge of
klao@959: 	/// node
klao@959: 	///@param g the graph
klao@959: 	EdgeIt(const StaticSymGraph& g) { }
klao@959: 	/// Edge -> EdgeIt conversion
klao@959: 
klao@959: 	/// Sets the iterator to the value of the trivial iterator \c e.
klao@959: 	/// This feature necessitates that each time we 
klao@959: 	/// iterate the edge-set, the iteration order is the same.
klao@959: 	EdgeIt(const StaticSymGraph&, const Edge&) { } 
klao@959:     	///Next edge
klao@959: 	
klao@959: 	/// Assign the iterator to the next 
klao@959: 	/// edge of the corresponding node.
klao@959: 	EdgeIt& operator++() { return *this; }
klao@959:       };
klao@959: 
klao@959:       /// First node of the graph.
klao@959: 
klao@959:       /// \retval i the first node.
klao@959:       /// \return the first node.
klao@959:       ///
klao@959:       NodeIt& first(NodeIt& i) const { return i; }
klao@959: 
klao@959:       /// The first incoming edge.
klao@959: 
klao@959:       /// The first incoming edge.
klao@959:       ///
klao@959:       InEdgeIt& first(InEdgeIt &i, Node) const { return i; }
klao@959:       /// The first outgoing edge.
klao@959: 
klao@959:       /// The first outgoing edge.
klao@959:       ///
klao@959:       OutEdgeIt& first(OutEdgeIt& i, Node) const { return i; }
klao@959:       /// The first edge of the Graph.
klao@959: 
klao@959:       /// The first edge of the Graph.
klao@959:       ///
klao@959:       EdgeIt& first(EdgeIt& i) const { return i; }
klao@959:       /// The first symmetric edge of the Graph.
klao@959: 
klao@959:       /// The first symmetric edge of the Graph.
klao@959:       ///
klao@959:       SymEdgeIt& first(SymEdgeIt& i) const { return i; }
klao@959: 
alpar@986:       ///Gives back the target node of an edge.
klao@959: 
alpar@986:       ///Gives back the target node of an edge.
klao@959:       ///
alpar@986:       Node target(Edge) const { return INVALID; }
alpar@986:       ///Gives back the source node of an edge.
klao@959: 
alpar@986:       ///Gives back the source node of an edge.
klao@959:       ///
alpar@986:       Node source(Edge) const { return INVALID; }
klao@959:   
klao@959:       ///Gives back the first node of an symmetric edge.
klao@959: 
klao@959:       ///Gives back the first node of an symmetric edge.
klao@959:       ///
alpar@986:       Node target(SymEdge) const { return INVALID; }
klao@959:       ///Gives back the second node of an symmetric edge.
klao@959: 
klao@959:       ///Gives back the second node of an symmetric edge.
klao@959:       ///
alpar@986:       Node source(SymEdge) const { return INVALID; }
klao@959:       ///Gives back the \e id of a node.
klao@959: 
klao@959:       ///\warning Not all graph structures provide this feature.
klao@959:       ///
klao@959:       ///\todo Should each graph provide \c id?
klao@959:       int id(const Node&) const { return 0; }
klao@959:       ///Gives back the \e id of an edge.
klao@959: 
klao@959:       ///\warning Not all graph structures provide this feature.
klao@959:       ///
klao@959:       ///\todo Should each graph provide \c id?
klao@959:       int id(const Edge&) const { return 0; }
klao@959: 
klao@959:       ///\warning Not all graph structures provide this feature.
klao@959:       ///
klao@959:       ///\todo Should each graph provide \c id?
klao@959:       int id(const SymEdge&) const { return 0; }
klao@959: 
klao@959:       ///\e
klao@959:       
klao@959:       ///\todo Should it be in the concept?
klao@959:       ///
klao@959:       int nodeNum() const { return 0; }
klao@959:       ///\e
klao@959: 
klao@959:       ///\todo Should it be in the concept?
klao@959:       ///
klao@959:       int edgeNum() const { return 0; }
klao@959: 
klao@959:       ///\todo Should it be in the concept?
klao@959:       ///
klao@959:       int symEdgeNum() const { return 0; }
klao@959: 
klao@959: 
klao@959:       /// Gives back the forward directed edge of the symmetric edge.
klao@959:       Edge forward(SymEdge) const {return INVALID;} 
klao@959: 
klao@959:       /// Gives back the backward directed edge of the symmetric edge.
klao@959:       Edge backward(SymEdge) const {return INVALID;};
klao@959: 
klao@959:       /// Gives back the opposite of the edge.
klao@959:       Edge opposite(Edge) const {return INVALID;}
klao@959: 
klao@959:       ///Reference map of the nodes to type \c T.
klao@959:       /// \ingroup concept
klao@959:       ///Reference map of the nodes to type \c T.
klao@959:       /// \sa Reference
klao@959:       /// \warning Making maps that can handle bool type (NodeMap<bool>)
klao@959:       /// needs some extra attention!
klao@959:       template<class T> class NodeMap : public ReferenceMap< Node, T >
klao@959:       {
klao@959:       public:
klao@959: 
klao@959: 	///\e
klao@959: 	NodeMap(const StaticSymGraph&) { }
klao@959: 	///\e
klao@959: 	NodeMap(const StaticSymGraph&, T) { }
klao@959: 
klao@959: 	///Copy constructor
klao@959: 	template<typename TT> NodeMap(const NodeMap<TT>&) { }
klao@959: 	///Assignment operator
klao@959: 	template<typename TT> NodeMap& operator=(const NodeMap<TT>&)
klao@959: 	{ return *this; }
klao@959:       };
klao@959: 
klao@959:       ///Reference map of the edges to type \c T.
klao@959: 
klao@959:       /// \ingroup concept
klao@959:       ///Reference map of the edges to type \c T.
klao@959:       /// \sa Reference
klao@959:       /// \warning Making maps that can handle bool type (EdgeMap<bool>)
klao@959:       /// needs some extra attention!
klao@959:       template<class T> class EdgeMap
klao@959: 	: public ReferenceMap<Edge,T>
klao@959:       {
klao@959:       public:
klao@959: 
klao@959: 	///\e
klao@959: 	EdgeMap(const StaticSymGraph&) { }
klao@959: 	///\e
klao@959: 	EdgeMap(const StaticSymGraph&, T) { }
klao@959:     
klao@959: 	///Copy constructor
klao@959: 	template<typename TT> EdgeMap(const EdgeMap<TT>&) { }
klao@959: 	///Assignment operator
klao@959: 	template<typename TT> EdgeMap &operator=(const EdgeMap<TT>&)
klao@959: 	{ return *this; }
klao@959:       };
klao@959: 
klao@959:       ///Reference map of the edges to type \c T.
klao@959: 
klao@959:       /// \ingroup concept
klao@959:       ///Reference map of the symmetric edges to type \c T.
klao@959:       /// \sa Reference
klao@959:       /// \warning Making maps that can handle bool type (EdgeMap<bool>)
klao@959:       /// needs some extra attention!
klao@959:       template<class T> class SymEdgeMap
klao@959: 	: public ReferenceMap<SymEdge,T>
klao@959:       {
klao@959:       public:
klao@959: 
klao@959: 	///\e
klao@959: 	SymEdgeMap(const StaticSymGraph&) { }
klao@959: 	///\e
klao@959: 	SymEdgeMap(const StaticSymGraph&, T) { }
klao@959:     
klao@959: 	///Copy constructor
klao@959: 	template<typename TT> SymEdgeMap(const SymEdgeMap<TT>&) { }
klao@959: 	///Assignment operator
klao@959: 	template<typename TT> SymEdgeMap &operator=(const SymEdgeMap<TT>&)
klao@959: 	{ return *this; }
klao@959:       };
klao@959:     };
klao@959: 
klao@959: 
klao@959:   
klao@959:     /// An empty non-static graph class.
klao@959: 
klao@959:     /// This class provides everything that \ref StaticGraph
klao@959:     /// with additional functionality which enables to build a
klao@959:     /// graph from scratch.
klao@959:     class ExtendableSymGraph : public StaticSymGraph
klao@959:     {
klao@959:     public:
klao@959:       /// Defalult constructor.
klao@959: 
klao@959:       /// Defalult constructor.
klao@959:       ///
klao@959:       ExtendableSymGraph() { }
klao@959:       ///Add a new node to the graph.
klao@959: 
klao@959:       /// \return the new node.
klao@959:       ///
klao@959:       Node addNode() { return INVALID; }
klao@959:       ///Add a new edge to the graph.
klao@959: 
alpar@986:       ///Add a new symmetric edge to the graph with source node \c t
alpar@986:       ///and target node \c h.
klao@959:       ///\return the new edge.
klao@959:       SymEdge addEdge(Node h, Node t) { return INVALID; }
klao@959:     
klao@959:       /// Resets the graph.
klao@959: 
klao@959:       /// This function deletes all edges and nodes of the graph.
klao@959:       /// It also frees the memory allocated to store them.
klao@959:       /// \todo It might belong to \ref ErasableGraph.
klao@959:       void clear() { }
klao@959:     };
klao@959: 
klao@959:     /// An empty erasable graph class.
klao@959:   
klao@959:     /// This class is an extension of \ref ExtendableGraph. It also makes it
klao@959:     /// possible to erase edges or nodes.
klao@959:     class ErasableSymGraph : public ExtendableSymGraph
klao@959:     {
klao@959:     public:
klao@959:       /// Defalult constructor.
klao@959: 
klao@959:       /// Defalult constructor.
klao@959:       ///
klao@959:       ErasableSymGraph() { }
klao@959:       /// Deletes a node.
klao@959: 
klao@959:       /// Deletes node \c n node.
klao@959:       ///
klao@959:       void erase(Node n) { }
klao@959:       /// Deletes an edge.
klao@959: 
klao@959:       /// Deletes edge \c e edge.
klao@959:       ///
klao@959:       void erase(SymEdge e) { }
klao@959:     };
klao@959: 
klao@959:     // @}
klao@959:   } //namespace concept  
klao@959: } //namespace lemon
klao@959: 
klao@959: 
klao@959: 
klao@959: #endif // LEMON_CONCEPT_GRAPH_H