deba@2126: /* -*- C++ -*-
deba@2126:  *
deba@2126:  * This file is a part of LEMON, a generic C++ optimization library
deba@2126:  *
deba@2126:  * Copyright (C) 2003-2006
deba@2126:  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
deba@2126:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
deba@2126:  *
deba@2126:  * Permission to use, modify and distribute this software is granted
deba@2126:  * provided that this copyright notice appears in all copies. For
deba@2126:  * precise terms see the accompanying LICENSE file.
deba@2126:  *
deba@2126:  * This software is provided "AS IS" with no warranty of any kind,
deba@2126:  * express or implied, and with no claim as to its suitability for any
deba@2126:  * purpose.
deba@2126:  *
deba@2126:  */
deba@2126: 
deba@2126: ///\ingroup graph_concepts
deba@2126: ///\file
deba@2126: ///\brief The concept of the graph components.
deba@2126: 
deba@2126: 
deba@2126: #ifndef LEMON_CONCEPT_GRAPH_COMPONENTS_H
deba@2126: #define LEMON_CONCEPT_GRAPH_COMPONENTS_H
deba@2126: 
deba@2126: #include <lemon/bits/invalid.h>
deba@2126: #include <lemon/concept/maps.h>
deba@2126: 
deba@2126: #include <lemon/bits/alteration_notifier.h>
deba@2126: 
deba@2126: namespace lemon {
deba@2126:   namespace concept {
deba@2126: 
deba@2126:     /// \brief Skeleton class for graph Node and Edge types
deba@2126:     ///
deba@2126:     /// This class describes the interface of Node and Edge (and UEdge
deba@2126:     /// in undirected graphs) subtypes of graph types.
deba@2126:     ///
deba@2126:     /// \note This class is a template class so that we can use it to
deba@2126:     /// create graph skeleton classes. The reason for this is than Node
deba@2126:     /// and Edge types should \em not derive from the same base class.
deba@2126:     /// For Node you should instantiate it with character 'n' and for Edge
deba@2126:     /// with 'e'.
deba@2126: 
deba@2126: #ifndef DOXYGEN
deba@2126:     template <char _selector = '0'>
deba@2126: #endif
deba@2126:     class GraphItem {
deba@2126:     public:
deba@2126:       /// \brief Default constructor.
deba@2126:       ///      
deba@2126:       /// \warning The default constructor is not required to set
deba@2126:       /// the item to some well-defined value. So you should consider it
deba@2126:       /// as uninitialized.
deba@2126:       GraphItem() {}
deba@2126:       /// \brief Copy constructor.
deba@2126:       ///
deba@2126:       /// Copy constructor.
deba@2126:       ///
deba@2126:       GraphItem(const GraphItem &) {}
deba@2126:       /// \brief Invalid constructor \& conversion.
deba@2126:       ///
deba@2126:       /// This constructor initializes the item to be invalid.
deba@2126:       /// \sa Invalid for more details.
deba@2126:       GraphItem(Invalid) {}
deba@2126:       /// \brief Assign operator for nodes.
deba@2126:       ///
deba@2126:       /// The nodes are assignable. 
deba@2126:       ///
deba@2126:       GraphItem& operator=(GraphItem const&) { return *this; }
deba@2126:       /// \brief Equality operator.
deba@2126:       ///
deba@2126:       /// Two iterators are equal if and only if they represents the
deba@2126:       /// same node in the graph or both are invalid.
deba@2126:       bool operator==(GraphItem) const { return false; }
deba@2126:       /// \brief Inequality operator.
deba@2126:       ///
deba@2126:       /// \sa operator==(const Node& n)
deba@2126:       ///
deba@2126:       bool operator!=(GraphItem) const { return false; }
deba@2126: 
deba@2126:       /// \brief Artificial ordering operator.
deba@2126:       ///
deba@2126:       /// To allow the use of graph descriptors as key type in std::map or
deba@2126:       /// similar associative container we require this.
deba@2126:       ///
deba@2126:       /// \note This operator only have to define some strict ordering of
deba@2126:       /// the items; this order has nothing to do with the iteration
deba@2126:       /// ordering of the items.
deba@2126:       bool operator<(GraphItem) const { return false; }
deba@2126: 
deba@2126:       template<typename _GraphItem>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  _GraphItem i1;
deba@2126: 	  _GraphItem i2 = i1;
deba@2126: 	  _GraphItem i3 = INVALID;
deba@2126: 	  
deba@2126: 	  i1 = i2 = i3;
deba@2126: 
deba@2126: 	  bool b;
deba@2126: 	  //	  b = (ia == ib) && (ia != ib) && (ia < ib);
deba@2126: 	  b = (ia == ib) && (ia != ib);
deba@2126: 	  b = (ia == INVALID) && (ib != INVALID);
deba@2126:           b = (ia < ib);
deba@2126: 	}
deba@2126: 
deba@2126: 	const _GraphItem &ia;
deba@2126: 	const _GraphItem &ib;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty base graph class.
deba@2126:     ///  
deba@2126:     /// This class provides the minimal set of features needed for a graph
deba@2126:     /// structure. All graph concepts have to be conform to this base
deba@2126:     /// graph. It just provides types for nodes and edges and functions to
deba@2126:     /// get the source and the target of the edges.
deba@2126:     class BaseGraphComponent {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef BaseGraphComponent Graph;
deba@2126:       
deba@2126:       /// \brief Node class of the graph.
deba@2126:       ///
deba@2126:       /// This class represents the Nodes of the graph. 
deba@2126:       ///
deba@2126:       typedef GraphItem<'n'> Node;
deba@2126: 
deba@2126:       /// \brief Edge class of the graph.
deba@2126:       ///
deba@2126:       /// This class represents the Edges of the graph. 
deba@2126:       ///
deba@2126:       typedef GraphItem<'e'> Edge;
deba@2126: 
deba@2126:       /// \brief Gives back the target node of an edge.
deba@2126:       ///
deba@2126:       /// Gives back the target node of an edge.
deba@2126:       ///
deba@2126:       Node target(const Edge&) const { return INVALID;}
deba@2126: 
deba@2126:       /// \brief Gives back the source node of an edge.
deba@2126:       ///
deba@2126:       /// Gives back the source node of an edge.
deba@2126:       ///
deba@2126:       Node source(const Edge&) const { return INVALID;}
deba@2126: 
deba@2126:       /// \brief Gives back the opposite node on the given edge.
deba@2126:       ///
deba@2126:       /// Gives back the opposite node on the given edge.
deba@2126:       Node oppositeNode(const Node&, const Edge&) const {
deba@2126:         return INVALID;
deba@2126:       }
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 	typedef typename _Graph::Node Node;
deba@2126: 	typedef typename _Graph::Edge Edge;
deba@2126:       
deba@2126: 	void constraints() {
deba@2126: 	  checkConcept<GraphItem<'n'>, Node>();
deba@2126: 	  checkConcept<GraphItem<'e'>, Edge>();
deba@2126: 	  {
deba@2126: 	    Node n;
deba@2126: 	    Edge e(INVALID);
deba@2126: 	    n = graph.source(e);
deba@2126: 	    n = graph.target(e);
deba@2126:             n = graph.oppositeNode(n, e);
deba@2126: 	  }      
deba@2126: 	}
deba@2126:       
deba@2126: 	const _Graph& graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty base undirected graph class.
deba@2126:     ///  
deba@2126:     /// This class provides the minimal set of features needed for an
deba@2126:     /// undirected graph structure. All undirected graph concepts have
deba@2126:     /// to be conform to this base graph. It just provides types for
deba@2126:     /// nodes, edges and undirected edges and functions to get the
deba@2126:     /// source and the target of the edges and undirected edges,
deba@2126:     /// conversion from edges to undirected edges and function to get
deba@2126:     /// both direction of the undirected edges.
deba@2126:     class BaseUGraphComponent : public BaseGraphComponent {
deba@2126:     public:
deba@2126:       typedef BaseGraphComponent::Node Node;
deba@2126:       typedef BaseGraphComponent::Edge Edge;
deba@2126:       /// \brief Undirected edge class of the graph.
deba@2126:       ///
deba@2126:       /// This class represents the undirected edges of the graph.
deba@2126:       /// The undirected graphs can be used as a directed graph which
deba@2126:       /// for each edge contains the opposite edge too so the graph is
deba@2126:       /// bidirected. The undirected edge represents two opposite
deba@2126:       /// directed edges.
deba@2126:       class UEdge : public GraphItem<'u'> {
deba@2126:       public:
deba@2126:         typedef GraphItem<'u'> Parent;
deba@2126:         /// \brief Default constructor.
deba@2126:         ///      
deba@2126:         /// \warning The default constructor is not required to set
deba@2126:         /// the item to some well-defined value. So you should consider it
deba@2126:         /// as uninitialized.
deba@2126:         UEdge() {}
deba@2126:         /// \brief Copy constructor.
deba@2126:         ///
deba@2126:         /// Copy constructor.
deba@2126:         ///
deba@2126:         UEdge(const UEdge &) : Parent() {}
deba@2126:         /// \brief Invalid constructor \& conversion.
deba@2126:         ///
deba@2126:         /// This constructor initializes the item to be invalid.
deba@2126:         /// \sa Invalid for more details.
deba@2126:         UEdge(Invalid) {}
deba@2126:         /// \brief Converter from edge to undirected edge.
deba@2126:         ///
deba@2126:         /// Besides the core graph item functionality each edge should
deba@2126:         /// be convertible to the represented undirected edge. 
deba@2126:         UEdge(const Edge&) {}
deba@2126:       };
deba@2126: 
deba@2126:       /// \brief Returns the direction of the edge.
deba@2126:       ///
deba@2126:       /// Returns the direction of the edge. Each edge represents an
deba@2126:       /// undirected edge with a direction. It gives back the
deba@2126:       /// direction.
deba@2126:       bool direction(const Edge&) const { return true; }
deba@2126: 
deba@2126:       /// \brief Returns the directed edge.
deba@2126:       ///
deba@2126:       /// Returns the directed edge from its direction and the
deba@2126:       /// represented undirected edge.
deba@2126:       Edge direct(const UEdge&, bool) const { return INVALID;} 
deba@2126: 
deba@2126:       /// \brief Returns the directed edge.
deba@2126:       ///
deba@2126:       /// Returns the directed edge from its source and the
deba@2126:       /// represented undirected edge.
deba@2126:       Edge direct(const UEdge&, const Node&) const { return INVALID;} 
deba@2126: 
deba@2126:       /// \brief Returns the opposite edge.
deba@2126:       ///
deba@2126:       /// Returns the opposite edge. It is the edge representing the
deba@2126:       /// same undirected edge and has opposite direction.
deba@2126:       Edge oppositeEdge(const Edge&) const { return INVALID;}
deba@2126: 
deba@2126:       /// \brief Gives back the target node of an undirected edge.
deba@2126:       ///
deba@2126:       /// Gives back the target node of an undirected edge. The name
deba@2126:       /// target is a little confusing because the undirected edge
deba@2126:       /// does not have target but it just means that one of the end 
deba@2126:       /// node.
deba@2126:       Node target(const UEdge&) const { return INVALID;}
deba@2126: 
deba@2126:       /// \brief Gives back the source node of an undirected edge.
deba@2126:       ///
deba@2126:       /// Gives back the source node of an undirected edge. The name
deba@2126:       /// source is a little confusing because the undirected edge
deba@2126:       /// does not have source but it just means that one of the end 
deba@2126:       /// node.
deba@2126:       Node source(const UEdge&) const { return INVALID;}
deba@2126:       
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 	typedef typename _Graph::Node Node;
deba@2126: 	typedef typename _Graph::Edge Edge;
deba@2126: 	typedef typename _Graph::UEdge UEdge;
deba@2126:       
deba@2126: 	void constraints() {
deba@2126:           checkConcept<BaseGraphComponent, _Graph>();
deba@2126: 	  checkConcept<GraphItem<'u'>, UEdge>();
deba@2126: 	  {
deba@2126: 	    Node n;
deba@2126: 	    UEdge ue(INVALID);
deba@2126:             Edge e;
deba@2126: 	    n = graph.source(ue);
deba@2126: 	    n = graph.target(ue);
deba@2126:             e = graph.direct(ue, true);
deba@2126:             e = graph.direct(ue, n);
deba@2126:             e = graph.oppositeEdge(e);
deba@2126:             ue = e;
deba@2126:             bool d = graph.direction(e);
deba@2126:             ignore_unused_variable_warning(d);
deba@2126: 	  }      
deba@2126: 	}
deba@2126:       
deba@2126: 	const _Graph& graph;
deba@2126:       };
deba@2126: 
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty iterable base graph class.
deba@2126:     ///  
deba@2126:     /// This class provides beside the core graph features
deba@2126:     /// core iterable interface for the graph structure.
deba@2126:     /// Most of the base graphs should be conform to this concept.
deba@2126:     template <typename _Base = BaseGraphComponent>
deba@2126:     class BaseIterableGraphComponent : public _Base {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef _Base Base; 
deba@2126:       typedef typename Base::Node Node;
deba@2126:       typedef typename Base::Edge Edge;
deba@2126: 
deba@2126:       /// \brief Gives back the first node in the iterating order.
deba@2126:       ///      
deba@2126:       /// Gives back the first node in the iterating order.
deba@2126:       ///     
deba@2126:       void first(Node&) const {}
deba@2126: 
deba@2126:       /// \brief Gives back the next node in the iterating order.
deba@2126:       ///
deba@2126:       /// Gives back the next node in the iterating order.
deba@2126:       ///     
deba@2126:       void next(Node&) const {}
deba@2126: 
deba@2126:       /// \brief Gives back the first edge in the iterating order.
deba@2126:       ///
deba@2126:       /// Gives back the first edge in the iterating order.
deba@2126:       ///     
deba@2126:       void first(Edge&) const {}
deba@2126: 
deba@2126:       /// \brief Gives back the next edge in the iterating order.
deba@2126:       ///
deba@2126:       /// Gives back the next edge in the iterating order.
deba@2126:       ///     
deba@2126:       void next(Edge&) const {}
deba@2126: 
deba@2126: 
deba@2126:       /// \brief Gives back the first of the edges point to the given
deba@2126:       /// node.
deba@2126:       ///
deba@2126:       /// Gives back the first of the edges point to the given node.
deba@2126:       ///     
deba@2126:       void firstIn(Edge&, const Node&) const {}
deba@2126: 
deba@2126:       /// \brief Gives back the next of the edges points to the given
deba@2126:       /// node.
deba@2126:       ///
deba@2126:       /// Gives back the next of the edges points to the given node.
deba@2126:       ///
deba@2126:       void nextIn(Edge&) const {}
deba@2126: 
deba@2126:       /// \brief Gives back the first of the edges start from the
deba@2126:       /// given node.
deba@2126:       ///      
deba@2126:       /// Gives back the first of the edges start from the given node.
deba@2126:       ///     
deba@2126:       void firstOut(Edge&, const Node&) const {}
deba@2126: 
deba@2126:       /// \brief Gives back the next of the edges start from the given
deba@2126:       /// node.
deba@2126:       ///
deba@2126:       /// Gives back the next of the edges start from the given node.
deba@2126:       ///     
deba@2126:       void nextOut(Edge&) const {}
deba@2126: 
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126:       
deba@2126: 	void constraints() {
deba@2126: 	  checkConcept< BaseGraphComponent, _Graph >();
deba@2129: 	  typename _Graph::Node node(INVALID);      
deba@2129: 	  typename _Graph::Edge edge(INVALID);
deba@2126: 	  {
deba@2126: 	    graph.first(node);
deba@2126: 	    graph.next(node);
deba@2126: 	  }
deba@2126: 	  {
deba@2126: 	    graph.first(edge);
deba@2126: 	    graph.next(edge);
deba@2126: 	  }
deba@2126: 	  {
deba@2126: 	    graph.firstIn(edge, node);
deba@2126: 	    graph.nextIn(edge);
deba@2126: 	  }
deba@2126: 	  {
deba@2126: 	    graph.firstOut(edge, node);
deba@2126: 	    graph.nextOut(edge);
deba@2126: 	  }
deba@2126: 	}
deba@2126: 
deba@2126: 	const _Graph& graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty iterable base undirected graph class.
deba@2126:     ///  
deba@2126:     /// This class provides beside the core undirceted graph features
deba@2126:     /// core iterable interface for the undirected graph structure.
deba@2126:     /// Most of the base undirected graphs should be conform to this
deba@2126:     /// concept.
deba@2126:     template <typename _Base = BaseUGraphComponent>
deba@2126:     class BaseIterableUGraphComponent 
deba@2126:       : public BaseIterableGraphComponent<_Base> {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef _Base Base; 
deba@2126:       typedef typename Base::UEdge UEdge;
deba@2126:       typedef typename Base::Node Node;
deba@2126: 
deba@2126:       using BaseIterableGraphComponent<_Base>::first;
deba@2126:       using BaseIterableGraphComponent<_Base>::next;
deba@2126: 
deba@2126:       /// \brief Gives back the first undirected edge in the iterating
deba@2126:       /// order.
deba@2126:       ///
deba@2126:       /// Gives back the first undirected edge in the iterating order.
deba@2126:       ///     
deba@2126:       void first(UEdge&) const {}
deba@2126: 
deba@2126:       /// \brief Gives back the next undirected edge in the iterating
deba@2126:       /// order.
deba@2126:       ///
deba@2126:       /// Gives back the next undirected edge in the iterating order.
deba@2126:       ///     
deba@2126:       void next(UEdge&) const {}
deba@2126: 
deba@2126: 
deba@2126:       /// \brief Gives back the first of the undirected edges from the
deba@2126:       /// given node.
deba@2126:       ///
deba@2126:       /// Gives back the first of the undirected edges from the given
deba@2126:       /// node. The bool parameter gives back that direction which
deba@2126:       /// gives a good direction of the uedge so the source of the
deba@2126:       /// directed edge is the given node.
deba@2126:       void firstInc(UEdge&, bool&, const Node&) const {}
deba@2126: 
deba@2126:       /// \brief Gives back the next of the undirected edges from the
deba@2126:       /// given node.
deba@2126:       ///
deba@2126:       /// Gives back the next of the undirected edges from the given
deba@2126:       /// node. The bool parameter should be used as the \c firstInc()
deba@2126:       /// use it.
deba@2126:       void nextInc(UEdge&, bool&) const {}
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126:       
deba@2126: 	void constraints() {
deba@2126: 	  checkConcept<Base, _Graph >();
deba@2126: 	  checkConcept<BaseIterableGraphComponent<Base>, _Graph>();
deba@2129: 	  typename _Graph::Node node(INVALID);
deba@2129: 	  typename _Graph::UEdge uedge(INVALID);
deba@2126:           bool dir;
deba@2126: 	  {
deba@2126: 	    graph.first(uedge);
deba@2126: 	    graph.next(uedge);
deba@2126: 	  }
deba@2126: 	  {
deba@2126: 	    graph.firstInc(uedge, dir, node);
deba@2126: 	    graph.nextInc(uedge, dir);
deba@2126: 	  }
deba@2126: 	}
deba@2126: 
deba@2126: 	const _Graph& graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty idable base graph class.
deba@2126:     ///  
deba@2126:     /// This class provides beside the core graph features
deba@2126:     /// core id functions for the graph structure.
deba@2126:     /// The most of the base graphs should be conform to this concept.
deba@2126:     /// The id's are unique and immutable.
deba@2126:     template <typename _Base = BaseGraphComponent>
deba@2126:     class IDableGraphComponent : public _Base {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef _Base Base;
deba@2126:       typedef typename Base::Node Node;
deba@2126:       typedef typename Base::Edge Edge;
deba@2126: 
deba@2126:       /// \brief Gives back an unique integer id for the Node. 
deba@2126:       ///
deba@2126:       /// Gives back an unique integer id for the Node. 
deba@2126:       ///
deba@2126:       int id(const Node&) const { return -1;}
deba@2126: 
deba@2126:       /// \brief Gives back the node by the unique id.
deba@2126:       ///
deba@2126:       /// Gives back the node by the unique id.
deba@2126:       /// If the graph does not contain node with the given id
deba@2126:       /// then the result of the function is undetermined. 
deba@2126:       Node nodeFromId(int) const { return INVALID;}
deba@2126: 
deba@2126:       /// \brief Gives back an unique integer id for the Edge. 
deba@2126:       ///
deba@2126:       /// Gives back an unique integer id for the Edge. 
deba@2126:       ///
deba@2126:       int id(const Edge&) const { return -1;}
deba@2126: 
deba@2126:       /// \brief Gives back the edge by the unique id.
deba@2126:       ///
deba@2126:       /// Gives back the edge by the unique id.
deba@2126:       /// If the graph does not contain edge with the given id
deba@2126:       /// then the result of the function is undetermined. 
deba@2126:       Edge edgeFromId(int) const { return INVALID;}
deba@2126: 
deba@2126:       /// \brief Gives back an integer greater or equal to the maximum
deba@2126:       /// Node id.
deba@2126:       ///
deba@2126:       /// Gives back an integer greater or equal to the maximum Node
deba@2126:       /// id.
deba@2126:       int maxNodeId() const { return -1;}
deba@2126: 
deba@2126:       /// \brief Gives back an integer greater or equal to the maximum
deba@2126:       /// Edge id.
deba@2126:       ///
deba@2126:       /// Gives back an integer greater or equal to the maximum Edge
deba@2126:       /// id.
deba@2126:       int maxEdgeId() const { return -1;}
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 
deba@2126: 	void constraints() {
deba@2126: 	  checkConcept< BaseGraphComponent, _Graph >();
deba@2126: 	  typename _Graph::Node node;
deba@2126: 	  int nid = graph.id(node);
deba@2126: 	  nid = graph.id(node);
deba@2126: 	  node = graph.nodeFromId(nid);
deba@2126: 	  typename _Graph::Edge edge;
deba@2126: 	  int eid = graph.id(edge);
deba@2126: 	  eid = graph.id(edge);
deba@2126: 	  edge = graph.edgeFromId(eid);
deba@2126: 
deba@2126: 	  nid = graph.maxNodeId();
deba@2126: 	  ignore_unused_variable_warning(nid);
deba@2126: 	  eid = graph.maxEdgeId();
deba@2126: 	  ignore_unused_variable_warning(eid);
deba@2126: 	}
deba@2126: 
deba@2126: 	const _Graph& graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty idable base undirected graph class.
deba@2126:     ///  
deba@2126:     /// This class provides beside the core undirected graph features
deba@2126:     /// core id functions for the undirected graph structure.  The
deba@2126:     /// most of the base undirected graphs should be conform to this
deba@2126:     /// concept.  The id's are unique and immutable.
deba@2126:     template <typename _Base = BaseUGraphComponent>
deba@2126:     class IDableUGraphComponent : public IDableGraphComponent<_Base> {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef _Base Base;
deba@2126:       typedef typename Base::UEdge UEdge;
deba@2126: 
deba@2126:       using IDableGraphComponent<_Base>::id;
deba@2126: 
deba@2126:       /// \brief Gives back an unique integer id for the UEdge. 
deba@2126:       ///
deba@2126:       /// Gives back an unique integer id for the UEdge. 
deba@2126:       ///
deba@2126:       int id(const UEdge&) const { return -1;}
deba@2126: 
deba@2126:       /// \brief Gives back the undirected edge by the unique id.
deba@2126:       ///
deba@2126:       /// Gives back the undirected edge by the unique id.  If the
deba@2126:       /// graph does not contain edge with the given id then the
deba@2126:       /// result of the function is undetermined.
deba@2126:       UEdge uEdgeFromId(int) const { return INVALID;}
deba@2126: 
deba@2126:       /// \brief Gives back an integer greater or equal to the maximum
deba@2126:       /// UEdge id.
deba@2126:       ///
deba@2126:       /// Gives back an integer greater or equal to the maximum UEdge
deba@2126:       /// id.
deba@2126:       int maxUEdgeId() const { return -1;}
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 
deba@2126: 	void constraints() {
deba@2126: 	  checkConcept<Base, _Graph >();
deba@2126: 	  checkConcept<IDableGraphComponent<Base>, _Graph >();
deba@2126: 	  typename _Graph::UEdge uedge;
deba@2126: 	  int ueid = graph.id(uedge);
deba@2126: 	  ueid = graph.id(uedge);
deba@2126: 	  uedge = graph.uEdgeFromId(ueid);
deba@2126: 	  ueid = graph.maxUEdgeId();
deba@2126: 	  ignore_unused_variable_warning(ueid);
deba@2126: 	}
deba@2126: 
deba@2126: 	const _Graph& graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty extendable base graph class.
deba@2126:     ///
deba@2126:     /// This class provides beside the core graph features
deba@2126:     /// core graph extend interface for the graph structure.
deba@2126:     /// The most of the base graphs should be conform to this concept.
deba@2126:     template <typename _Base = BaseGraphComponent>
deba@2126:     class BaseExtendableGraphComponent : public _Base {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef typename _Base::Node Node;
deba@2126:       typedef typename _Base::Edge Edge;
deba@2126: 
deba@2126:       /// \brief Adds a new node to the graph.
deba@2126:       ///
deba@2126:       /// Adds a new node to the graph.
deba@2126:       ///
deba@2126:       Node addNode() {
deba@2126: 	return INVALID;
deba@2126:       }
deba@2126:     
deba@2126:       /// \brief Adds a new edge connects the given two nodes.
deba@2126:       ///
deba@2126:       /// Adds a new edge connects the the given two nodes.
deba@2126:       Edge addEdge(const Node&, const Node&) {
deba@2126: 	return INVALID;
deba@2126:       }
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  typename _Graph::Node node_a, node_b;
deba@2126: 	  node_a = graph.addNode();
deba@2126: 	  node_b = graph.addNode();
deba@2126: 	  typename _Graph::Edge edge;
deba@2126: 	  edge = graph.addEdge(node_a, node_b);
deba@2126: 	}
deba@2126: 
deba@2126: 	_Graph& graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty extendable base undirected graph class.
deba@2126:     ///
deba@2126:     /// This class provides beside the core undirected graph features
deba@2126:     /// core undircted graph extend interface for the graph structure.
deba@2126:     /// The most of the base graphs should be conform to this concept.
deba@2126:     template <typename _Base = BaseUGraphComponent>
deba@2126:     class BaseExtendableUGraphComponent : public _Base {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef typename _Base::Node Node;
deba@2126:       typedef typename _Base::UEdge UEdge;
deba@2126: 
deba@2126:       /// \brief Adds a new node to the graph.
deba@2126:       ///
deba@2126:       /// Adds a new node to the graph.
deba@2126:       ///
deba@2126:       Node addNode() {
deba@2126: 	return INVALID;
deba@2126:       }
deba@2126:     
deba@2126:       /// \brief Adds a new edge connects the given two nodes.
deba@2126:       ///
deba@2126:       /// Adds a new edge connects the the given two nodes.
deba@2126:       UEdge addEdge(const Node&, const Node&) {
deba@2126: 	return INVALID;
deba@2126:       }
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  typename _Graph::Node node_a, node_b;
deba@2126: 	  node_a = graph.addNode();
deba@2126: 	  node_b = graph.addNode();
deba@2126: 	  typename _Graph::UEdge uedge;
deba@2126: 	  uedge = graph.addUEdge(node_a, node_b);
deba@2126: 	}
deba@2126: 
deba@2126: 	_Graph& graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty erasable base graph class.
deba@2126:     ///  
deba@2126:     /// This class provides beside the core graph features
deba@2126:     /// core erase functions for the graph structure.
deba@2126:     /// The most of the base graphs should be conform to this concept.
deba@2126:     template <typename _Base = BaseGraphComponent>
deba@2126:     class BaseErasableGraphComponent : public _Base {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef _Base Base;
deba@2126:       typedef typename Base::Node Node;
deba@2126:       typedef typename Base::Edge Edge;
deba@2126: 
deba@2126:       /// \brief Erase a node from the graph.
deba@2126:       ///
deba@2126:       /// Erase a node from the graph. This function should not
deba@2126:       /// erase edges connecting to the Node.
deba@2126:       void erase(const Node&) {}    
deba@2126: 
deba@2126:       /// \brief Erase an edge from the graph.
deba@2126:       ///
deba@2126:       /// Erase an edge from the graph.
deba@2126:       ///
deba@2126:       void erase(const Edge&) {}
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  typename _Graph::Node node;
deba@2126: 	  graph.erase(node);
deba@2126: 	  typename _Graph::Edge edge;
deba@2126: 	  graph.erase(edge);
deba@2126: 	}
deba@2126: 
deba@2126: 	_Graph& graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty erasable base undirected graph class.
deba@2126:     ///  
deba@2126:     /// This class provides beside the core undirected graph features
deba@2126:     /// core erase functions for the undirceted graph structure.
deba@2126:     template <typename _Base = BaseUGraphComponent>
deba@2126:     class BaseErasableUGraphComponent : public _Base {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef _Base Base;
deba@2126:       typedef typename Base::Node Node;
deba@2126:       typedef typename Base::UEdge UEdge;
deba@2126: 
deba@2126:       /// \brief Erase a node from the graph.
deba@2126:       ///
deba@2126:       /// Erase a node from the graph. This function should not
deba@2126:       /// erase edges connecting to the Node.
deba@2126:       void erase(const Node&) {}    
deba@2126: 
deba@2126:       /// \brief Erase an edge from the graph.
deba@2126:       ///
deba@2126:       /// Erase an edge from the graph.
deba@2126:       ///
deba@2126:       void erase(const UEdge&) {}
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  typename _Graph::Node node;
deba@2126: 	  graph.erase(node);
deba@2126: 	  typename _Graph::Edge edge;
deba@2126: 	  graph.erase(edge);
deba@2126: 	}
deba@2126: 
deba@2126: 	_Graph& graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty clearable base graph class.
deba@2126:     ///
deba@2126:     /// This class provides beside the core graph features
deba@2126:     /// core clear functions for the graph structure.
deba@2126:     /// The most of the base graphs should be conform to this concept.
deba@2126:     template <typename _Base = BaseGraphComponent>
deba@2126:     class BaseClearableGraphComponent : public _Base {
deba@2126:     public:
deba@2126: 
deba@2126:       /// \brief Erase all the nodes and edges from the graph.
deba@2126:       ///
deba@2126:       /// Erase all the nodes and edges from the graph.
deba@2126:       ///
deba@2126:       void clear() {}    
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  graph.clear();
deba@2126: 	}
deba@2126: 
deba@2126: 	_Graph graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty clearable base undirected graph class.
deba@2126:     ///
deba@2126:     /// This class provides beside the core undirected graph features
deba@2126:     /// core clear functions for the undirected graph structure.
deba@2126:     /// The most of the base graphs should be conform to this concept.
deba@2126:     template <typename _Base = BaseUGraphComponent>
deba@2126:     class BaseClearableUGraphComponent : public _Base {
deba@2126:     public:
deba@2126: 
deba@2126:       /// \brief Erase all the nodes and undirected edges from the graph.
deba@2126:       ///
deba@2126:       /// Erase all the nodes and undirected edges from the graph.
deba@2126:       ///
deba@2126:       void clear() {}    
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  graph.clear();
deba@2126: 	}
deba@2126: 
deba@2126: 	_Graph graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126: 
deba@2126:     /// \brief Skeleton class for graph NodeIt and EdgeIt
deba@2126:     ///
deba@2126:     /// Skeleton class for graph NodeIt and EdgeIt.
deba@2126:     ///
deba@2126:     template <typename _Graph, typename _Item>
deba@2126:     class GraphItemIt : public _Item {
deba@2126:     public:
deba@2126:       /// \brief Default constructor.
deba@2126:       ///
deba@2126:       /// @warning The default constructor sets the iterator
deba@2126:       /// to an undefined value.
deba@2126:       GraphItemIt() {}
deba@2126:       /// \brief Copy constructor.
deba@2126:       ///
deba@2126:       /// Copy constructor.
deba@2126:       ///
deba@2126:       GraphItemIt(const GraphItemIt& ) {}
deba@2126:       /// \brief Sets the iterator to the first item.
deba@2126:       ///
deba@2126:       /// Sets the iterator to the first item of \c the graph.
deba@2126:       ///
deba@2126:       explicit GraphItemIt(const _Graph&) {}
deba@2126:       /// \brief Invalid constructor \& conversion.
deba@2126:       ///
deba@2126:       /// This constructor initializes the item to be invalid.
deba@2126:       /// \sa Invalid for more details.
deba@2126:       GraphItemIt(Invalid) {}
deba@2126:       /// \brief Assign operator for items.
deba@2126:       ///
deba@2126:       /// The items are assignable. 
deba@2126:       ///
deba@2126:       GraphItemIt& operator=(const GraphItemIt&) { return *this; }      
deba@2126:       /// \brief Next item.
deba@2126:       /// 
deba@2126:       /// Assign the iterator to the next item.
deba@2126:       ///
deba@2126:       GraphItemIt& operator++() { return *this; }
deba@2126:       /// \brief Equality operator
deba@2126:       /// 
deba@2126:       /// Two iterators are equal if and only if they point to the
deba@2126:       /// same object or both are invalid.
deba@2126:       bool operator==(const GraphItemIt&) const { return true;}
deba@2126:       /// \brief Inequality operator
deba@2126:       ///	
deba@2126:       /// \sa operator==(Node n)
deba@2126:       ///
deba@2126:       bool operator!=(const GraphItemIt&) const { return true;}
deba@2126:       
deba@2126:       template<typename _GraphItemIt>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  _GraphItemIt it1(g);	
deba@2126: 	  _GraphItemIt it2;
deba@2126: 
deba@2126: 	  it2 = ++it1;
deba@2126: 	  ++it2 = it1;
deba@2126: 	  ++(++it1);
deba@2126: 
deba@2126: 	  _Item bi = it1;
deba@2126: 	  bi = it2;
deba@2126: 	}
deba@2126: 	_Graph& g;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief Skeleton class for graph InEdgeIt and OutEdgeIt
deba@2126:     ///
deba@2126:     /// \note Because InEdgeIt and OutEdgeIt may not inherit from the same
deba@2126:     /// base class, the _selector is a additional template parameter. For 
deba@2126:     /// InEdgeIt you should instantiate it with character 'i' and for 
deba@2126:     /// OutEdgeIt with 'o'.
deba@2126:     template <typename _Graph,
deba@2126: 	      typename _Item = typename _Graph::Edge,
deba@2126:               typename _Base = typename _Graph::Node, 
deba@2126: 	      char _selector = '0'>
deba@2126:     class GraphIncIt : public _Item {
deba@2126:     public:
deba@2126:       /// \brief Default constructor.
deba@2126:       ///
deba@2126:       /// @warning The default constructor sets the iterator
deba@2126:       /// to an undefined value.
deba@2126:       GraphIncIt() {}
deba@2126:       /// \brief Copy constructor.
deba@2126:       ///
deba@2126:       /// Copy constructor.
deba@2126:       ///
deba@2126:       GraphIncIt(GraphIncIt const& gi) : _Item(gi) {}
deba@2126:       /// \brief Sets the iterator to the first edge incoming into or outgoing 
deba@2126:       /// from the node.
deba@2126:       ///
deba@2126:       /// Sets the iterator to the first edge incoming into or outgoing 
deba@2126:       /// from the node.
deba@2126:       ///
deba@2126:       explicit GraphIncIt(const _Graph&, const _Base&) {}
deba@2126:       /// \brief Invalid constructor \& conversion.
deba@2126:       ///
deba@2126:       /// This constructor initializes the item to be invalid.
deba@2126:       /// \sa Invalid for more details.
deba@2126:       GraphIncIt(Invalid) {}
deba@2126:       /// \brief Assign operator for iterators.
deba@2126:       ///
deba@2126:       /// The iterators are assignable. 
deba@2126:       ///
deba@2126:       GraphIncIt& operator=(GraphIncIt const&) { return *this; }      
deba@2126:       /// \brief Next item.
deba@2126:       ///
deba@2126:       /// Assign the iterator to the next item.
deba@2126:       ///
deba@2126:       GraphIncIt& operator++() { return *this; }
deba@2126: 
deba@2126:       /// \brief Equality operator
deba@2126:       ///
deba@2126:       /// Two iterators are equal if and only if they point to the
deba@2126:       /// same object or both are invalid.
deba@2126:       bool operator==(const GraphIncIt&) const { return true;}
deba@2126: 
deba@2126:       /// \brief Inequality operator
deba@2126:       ///
deba@2126:       /// \sa operator==(Node n)
deba@2126:       ///
deba@2126:       bool operator!=(const GraphIncIt&) const { return true;}
deba@2126: 
deba@2126:       template <typename _GraphIncIt>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  checkConcept<GraphItem<_selector>, _GraphIncIt>();
deba@2126: 	  _GraphIncIt it1(graph, node);
deba@2126: 	  _GraphIncIt it2;
deba@2126: 
deba@2126: 	  it2 = ++it1;
deba@2126: 	  ++it2 = it1;
deba@2126: 	  ++(++it1);
deba@2126: 	  _Item e = it1;
deba@2126: 	  e = it2;
deba@2126: 
deba@2126: 	}
deba@2126: 
deba@2126: 	_Item edge;
deba@2126: 	_Base node;
deba@2126: 	_Graph graph;
deba@2126: 	_GraphIncIt it;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126: 
deba@2126:     /// \brief An empty iterable graph class.
deba@2126:     ///
deba@2126:     /// This class provides beside the core graph features
deba@2126:     /// iterator based iterable interface for the graph structure.
deba@2126:     /// This concept is part of the GraphConcept.
deba@2126:     template <typename _Base = BaseGraphComponent>
deba@2126:     class IterableGraphComponent : public _Base {
deba@2126: 
deba@2126:     public:
deba@2126:     
deba@2126:       typedef _Base Base;
deba@2126:       typedef typename Base::Node Node;
deba@2126:       typedef typename Base::Edge Edge;
deba@2126: 
deba@2126:       typedef IterableGraphComponent Graph;
deba@2126: 
deba@2126: 
deba@2126:       /// \brief This iterator goes through each node.
deba@2126:       ///
deba@2126:       /// This iterator goes through each node.
deba@2126:       ///
deba@2126:       typedef GraphItemIt<Graph, Node> NodeIt;
deba@2126: 
deba@2126:       /// \brief This iterator goes through each node.
deba@2126:       ///
deba@2126:       /// This iterator goes through each node.
deba@2126:       ///
deba@2126:       typedef GraphItemIt<Graph, Edge> EdgeIt;
deba@2126: 
deba@2126:       /// \brief This iterator goes trough the incoming edges of a node.
deba@2126:       ///
deba@2126:       /// This iterator goes trough the \e inccoming edges of a certain node
deba@2126:       /// of a graph.
deba@2126:       typedef GraphIncIt<Graph, Edge, Node, 'i'> InEdgeIt;
deba@2126: 
deba@2126:       /// \brief This iterator goes trough the outgoing edges of a node.
deba@2126:       ///
deba@2126:       /// This iterator goes trough the \e outgoing edges of a certain node
deba@2126:       /// of a graph.
deba@2126:       typedef GraphIncIt<Graph, Edge, Node, 'o'> OutEdgeIt;
deba@2126: 
deba@2126:       /// \brief The base node of the iterator.
deba@2126:       ///
deba@2126:       /// Gives back the base node of the iterator.
deba@2126:       /// It is always the target of the pointed edge.
deba@2126:       Node baseNode(const InEdgeIt&) const { return INVALID; }
deba@2126: 
deba@2126:       /// \brief The running node of the iterator.
deba@2126:       ///
deba@2126:       /// Gives back the running node of the iterator.
deba@2126:       /// It is always the source of the pointed edge.
deba@2126:       Node runningNode(const InEdgeIt&) const { return INVALID; }
deba@2126: 
deba@2126:       /// \brief The base node of the iterator.
deba@2126:       ///
deba@2126:       /// Gives back the base node of the iterator.
deba@2126:       /// It is always the source of the pointed edge.
deba@2126:       Node baseNode(const OutEdgeIt&) const { return INVALID; }
deba@2126: 
deba@2126:       /// \brief The running node of the iterator.
deba@2126:       ///
deba@2126:       /// Gives back the running node of the iterator.
deba@2126:       /// It is always the target of the pointed edge.
deba@2126:       Node runningNode(const OutEdgeIt&) const { return INVALID; }
deba@2126: 
deba@2126:       /// \brief The opposite node on the given edge.
deba@2126:       ///
deba@2126:       /// Gives back the opposite on the given edge.
deba@2126:       /// \todo It should not be here.
deba@2126:       Node oppositeNode(const Node&, const Edge&) const { return INVALID; }
deba@2126: 
deba@2126:     
deba@2126:       template <typename _Graph> 
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  checkConcept<Base, _Graph>();
deba@2126: 	  
deba@2126: 	  checkConcept<GraphItemIt<_Graph, typename _Graph::Edge>,
deba@2126: 	    typename _Graph::EdgeIt >();
deba@2126: 	  checkConcept<GraphItemIt<_Graph, typename _Graph::Node>,
deba@2126: 	    typename _Graph::NodeIt >();
deba@2126: 	  checkConcept<GraphIncIt<_Graph, typename _Graph::Edge, 
deba@2126:             typename _Graph::Node, 'i'>, typename _Graph::InEdgeIt>();
deba@2126: 	  checkConcept<GraphIncIt<_Graph, typename _Graph::Edge, 
deba@2126:             typename _Graph::Node, 'o'>, typename _Graph::OutEdgeIt>();
deba@2126: 
deba@2126:           typename _Graph::Node n;
deba@2126:           typename _Graph::InEdgeIt ieit(INVALID);
deba@2126:           typename _Graph::OutEdgeIt oeit(INVALID);
deba@2126:           n = graph.baseNode(ieit);
deba@2126:           n = graph.runningNode(ieit);
deba@2126:           n = graph.baseNode(oeit);
deba@2126:           n = graph.runningNode(oeit);
deba@2126:           ignore_unused_variable_warning(n);
deba@2126:         }
deba@2126: 	
deba@2126: 	const _Graph& graph;
deba@2126: 	
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty iterable undirected graph class.
deba@2126:     ///
deba@2126:     /// This class provides beside the core graph features iterator
deba@2126:     /// based iterable interface for the undirected graph structure.
deba@2126:     /// This concept is part of the GraphConcept.
deba@2126:     template <typename _Base = BaseUGraphComponent>
deba@2126:     class IterableUGraphComponent : public IterableGraphComponent<_Base> {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef _Base Base;
deba@2126:       typedef typename Base::Node Node;
deba@2126:       typedef typename Base::Edge Edge;
deba@2126:       typedef typename Base::UEdge UEdge;
deba@2126: 
deba@2126:     
deba@2126:       typedef IterableUGraphComponent Graph;
deba@2126:       using IterableGraphComponent<_Base>::baseNode;
deba@2126:       using IterableGraphComponent<_Base>::runningNode;
deba@2126: 
deba@2126: 
deba@2126:       /// \brief This iterator goes through each node.
deba@2126:       ///
deba@2126:       /// This iterator goes through each node.
deba@2126:       typedef GraphItemIt<Graph, UEdge> UEdgeIt;
deba@2126:       /// \brief This iterator goes trough the incident edges of a
deba@2126:       /// node.
deba@2126:       ///
deba@2126:       /// This iterator goes trough the incident edges of a certain
deba@2126:       /// node of a graph.
deba@2126:       typedef GraphIncIt<Graph, UEdge, Node, 'u'> IncEdgeIt;
deba@2126:       /// \brief The base node of the iterator.
deba@2126:       ///
deba@2126:       /// Gives back the base node of the iterator.
deba@2126:       Node baseNode(const IncEdgeIt&) const { return INVALID; }
deba@2126: 
deba@2126:       /// \brief The running node of the iterator.
deba@2126:       ///
deba@2126:       /// Gives back the running node of the iterator.
deba@2126:       Node runningNode(const IncEdgeIt&) const { return INVALID; }
deba@2126: 
deba@2126:       template <typename _Graph> 
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  checkConcept<Base, _Graph>();
deba@2126: 	  checkConcept<IterableGraphComponent<Base>, _Graph>();
deba@2126: 	  
deba@2126: 	  checkConcept<GraphItemIt<_Graph, typename _Graph::UEdge>,
deba@2126: 	    typename _Graph::UEdgeIt >();
deba@2126: 	  checkConcept<GraphIncIt<_Graph, typename _Graph::UEdge, 
deba@2126:             typename _Graph::Node, 'u'>, typename _Graph::IncEdgeIt>();
deba@2126: 
deba@2126:           typename _Graph::Node n;
deba@2126:           typename _Graph::IncEdgeIt ueit(INVALID);
deba@2126:           n = graph.baseNode(ueit);
deba@2126:           n = graph.runningNode(ueit);
deba@2126: 	}
deba@2126: 	
deba@2126: 	const _Graph& graph;
deba@2126: 	
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty alteration notifier graph class.
deba@2126:     ///  
deba@2126:     /// This class provides beside the core graph features alteration
deba@2126:     /// notifier interface for the graph structure.  This implements
deba@2126:     /// an observer-notifier pattern for each graph item. More
deba@2126:     /// obsevers can be registered into the notifier and whenever an
deba@2126:     /// alteration occured in the graph all the observers will
deba@2126:     /// notified about it.
deba@2126:     template <typename _Base = BaseGraphComponent>
deba@2126:     class AlterableGraphComponent : public _Base {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef _Base Base;
deba@2126:       typedef typename Base::Node Node;
deba@2126:       typedef typename Base::Edge Edge;
deba@2126: 
deba@2126: 
deba@2126:       /// The node observer registry.
deba@2126:       typedef AlterationNotifier<AlterableGraphComponent, Node> 
deba@2126:       NodeNotifier;
deba@2126:       /// The edge observer registry.
deba@2126:       typedef AlterationNotifier<AlterableGraphComponent, Edge> 
deba@2126:       EdgeNotifier;
deba@2126:       
deba@2126:       /// \brief Gives back the node alteration notifier.
deba@2126:       ///
deba@2126:       /// Gives back the node alteration notifier.
deba@2126:       NodeNotifier& getNotifier(Node) const {
deba@2126: 	return NodeNotifier();
deba@2126:       }
deba@2126:       
deba@2126:       /// \brief Gives back the edge alteration notifier.
deba@2126:       ///
deba@2126:       /// Gives back the edge alteration notifier.
deba@2126:       EdgeNotifier& getNotifier(Edge) const {
deba@2126: 	return EdgeNotifier();
deba@2126:       }
deba@2126: 
deba@2126:       template <typename _Graph> 
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  checkConcept<Base, _Graph>();
deba@2126:           typename _Graph::NodeNotifier& nn 
deba@2126:             = graph.getNotifier(typename _Graph::Node());
deba@2126: 
deba@2126:           typename _Graph::EdgeNotifier& en 
deba@2126:             = graph.getNotifier(typename _Graph::Edge());
deba@2126:           
deba@2126:           ignore_unused_variable_warning(nn);
deba@2126:           ignore_unused_variable_warning(en);
deba@2126: 	}
deba@2126: 	
deba@2126: 	const _Graph& graph;
deba@2126: 	
deba@2126:       };
deba@2126:       
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty alteration notifier undirected graph class.
deba@2126:     ///  
deba@2126:     /// This class provides beside the core graph features alteration
deba@2126:     /// notifier interface for the graph structure.  This implements
deba@2126:     /// an observer-notifier pattern for each graph item. More
deba@2126:     /// obsevers can be registered into the notifier and whenever an
deba@2126:     /// alteration occured in the graph all the observers will
deba@2126:     /// notified about it.
deba@2126:     template <typename _Base = BaseUGraphComponent>
deba@2126:     class AlterableUGraphComponent : public AlterableGraphComponent<_Base> {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef _Base Base;
deba@2126:       typedef typename Base::UEdge UEdge;
deba@2126: 
deba@2126: 
deba@2126:       /// The edge observer registry.
deba@2126:       typedef AlterationNotifier<AlterableUGraphComponent, UEdge> 
deba@2126:       UEdgeNotifier;
deba@2126:       
deba@2126:       /// \brief Gives back the edge alteration notifier.
deba@2126:       ///
deba@2126:       /// Gives back the edge alteration notifier.
deba@2126:       UEdgeNotifier& getNotifier(UEdge) const {
deba@2126: 	return UEdgeNotifier();
deba@2126:       }
deba@2126: 
deba@2126:       template <typename _Graph> 
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  checkConcept<Base, _Graph>();
deba@2126:           checkConcept<AlterableGraphComponent, _Graph>();
deba@2126:           typename _Graph::UEdgeNotifier& uen 
deba@2126:             = graph.getNotifier(typename _Graph::UEdge());
deba@2126:           ignore_unused_variable_warning(uen);
deba@2126: 	}
deba@2126: 	
deba@2126: 	const _Graph& graph;
deba@2126: 	
deba@2126:       };
deba@2126:       
deba@2126:     };
deba@2126: 
deba@2126: 
deba@2126:     /// \brief Class describing the concept of graph maps
deba@2126:     /// 
deba@2126:     /// This class describes the common interface of the graph maps
deba@2126:     /// (NodeMap, EdgeMap), that is \ref maps-page "maps" which can be used to
deba@2126:     /// associate data to graph descriptors (nodes or edges).
deba@2126:     template <typename _Graph, typename _Item, typename _Value>
deba@2126:     class GraphMap : public ReadWriteMap<_Item, _Value> {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef ReadWriteMap<_Item, _Value> Parent;
deba@2126: 
deba@2126:       /// The graph type of the map.
deba@2126:       typedef _Graph Graph;
deba@2126:       /// The key type of the map.
deba@2126:       typedef _Item Key;
deba@2126:       /// The value type of the map.
deba@2126:       typedef _Value Value;
deba@2126: 
deba@2126:       /// \brief Construct a new map.
deba@2126:       ///
deba@2126:       /// Construct a new map for the graph.
deba@2126:       explicit GraphMap(const Graph&) {}
deba@2126:       /// \brief Construct a new map with default value.
deba@2126:       ///
deba@2126:       /// Construct a new map for the graph and initalise the values.
deba@2126:       GraphMap(const Graph&, const Value&) {}
deba@2126:       /// \brief Copy constructor.
deba@2126:       ///
deba@2126:       /// Copy Constructor.
deba@2126:       GraphMap(const GraphMap&) : Parent() {}
deba@2126:       
deba@2126:       /// \brief Assign operator.
deba@2126:       ///
deba@2126:       /// Assign operator. It does not mofify the underlying graph,
deba@2126:       /// it just iterates on the current item set and set the  map
deba@2126:       /// with the value returned by the assigned map. 
deba@2126:       template <typename CMap>
deba@2126:       GraphMap& operator=(const CMap&) { 
deba@2126:         checkConcept<ReadMap<Key, Value>, CMap>();
deba@2126:         return *this;
deba@2126:       }
deba@2126: 
deba@2126:       template<typename _Map>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  checkConcept<ReadWriteMap<Key, Value>, _Map >();
deba@2126: 	  // Construction with a graph parameter
deba@2126: 	  _Map a(g);
deba@2126: 	  // Constructor with a graph and a default value parameter
deba@2126: 	  _Map a2(g,t);
deba@2126: 	  // Copy constructor.
deba@2126: 	  _Map b(c);
deba@2126:           
deba@2126:           ReadMap<Key, Value> cmap;
deba@2126:           b = cmap;
deba@2126: 
deba@2126: 	  ignore_unused_variable_warning(a2);
deba@2126: 	  ignore_unused_variable_warning(b);
deba@2126: 	}
deba@2126: 
deba@2126: 	const _Map &c;
deba@2126: 	const Graph &g;
deba@2126: 	const typename GraphMap::Value &t;
deba@2126:       };
deba@2126: 
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty mappable graph class.
deba@2126:     ///
deba@2126:     /// This class provides beside the core graph features
deba@2126:     /// map interface for the graph structure.
deba@2126:     /// This concept is part of the Graph concept.
deba@2126:     template <typename _Base = BaseGraphComponent>
deba@2126:     class MappableGraphComponent : public _Base  {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef _Base Base;
deba@2126:       typedef typename Base::Node Node;
deba@2126:       typedef typename Base::Edge Edge;
deba@2126: 
deba@2126:       typedef MappableGraphComponent Graph;
deba@2126: 
deba@2126:       /// \brief ReadWrite map of the nodes.
deba@2126:       ///
deba@2126:       /// ReadWrite map of the nodes.
deba@2126:       ///
deba@2126:       template <typename Value>
deba@2126:       class NodeMap : public GraphMap<Graph, Node, Value> {
deba@2126:       private:
deba@2126: 	NodeMap();
deba@2126:       public:
deba@2126:         typedef GraphMap<Graph, Node, Value> Parent;
deba@2126: 
deba@2126: 	/// \brief Construct a new map.
deba@2126: 	///
deba@2126: 	/// Construct a new map for the graph.
deba@2126: 	/// \todo call the right parent class constructor
deba@2126: 	explicit NodeMap(const Graph& graph) : Parent(graph) {}
deba@2126: 
deba@2126: 	/// \brief Construct a new map with default value.
deba@2126: 	///
deba@2126: 	/// Construct a new map for the graph and initalise the values.
deba@2126: 	NodeMap(const Graph& graph, const Value& value)
deba@2126:           : Parent(graph, value) {}
deba@2126: 
deba@2126: 	/// \brief Copy constructor.
deba@2126: 	///
deba@2126: 	/// Copy Constructor.
deba@2126: 	NodeMap(const NodeMap& nm) : Parent(nm) {}
deba@2126: 
deba@2126: 	/// \brief Assign operator.
deba@2126: 	///
deba@2126: 	/// Assign operator.
deba@2126:         template <typename CMap>
deba@2126:         NodeMap& operator=(const CMap&) { 
deba@2126:           checkConcept<ReadMap<Node, Value>, CMap>();
deba@2126:           return *this;
deba@2126:         }
deba@2126: 
deba@2126:       };
deba@2126: 
deba@2126:       /// \brief ReadWrite map of the edges.
deba@2126:       ///
deba@2126:       /// ReadWrite map of the edges.
deba@2126:       ///
deba@2126:       template <typename Value>
deba@2126:       class EdgeMap : public GraphMap<Graph, Edge, Value> {
deba@2126:       private:
deba@2126: 	EdgeMap();
deba@2126:       public:
deba@2126:         typedef GraphMap<Graph, Edge, Value> Parent;
deba@2126: 
deba@2126: 	/// \brief Construct a new map.
deba@2126: 	///
deba@2126: 	/// Construct a new map for the graph.
deba@2126: 	/// \todo call the right parent class constructor
deba@2126: 	explicit EdgeMap(const Graph& graph) : Parent(graph) {}
deba@2126: 
deba@2126: 	/// \brief Construct a new map with default value.
deba@2126: 	///
deba@2126: 	/// Construct a new map for the graph and initalise the values.
deba@2126: 	EdgeMap(const Graph& graph, const Value& value)
deba@2126:           : Parent(graph, value) {}
deba@2126: 
deba@2126: 	/// \brief Copy constructor.
deba@2126: 	///
deba@2126: 	/// Copy Constructor.
deba@2126: 	EdgeMap(const EdgeMap& nm) : Parent(nm) {}
deba@2126: 
deba@2126: 	/// \brief Assign operator.
deba@2126: 	///
deba@2126: 	/// Assign operator.
deba@2126:         template <typename CMap>
deba@2126:         EdgeMap& operator=(const CMap&) { 
deba@2126:           checkConcept<ReadMap<Edge, Value>, CMap>();
deba@2126:           return *this;
deba@2126:         }
deba@2126: 
deba@2126:       };
deba@2126: 
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 
deba@2126: 	struct Dummy {
deba@2126: 	  int value;
deba@2126: 	  Dummy() : value(0) {}
deba@2126: 	  Dummy(int _v) : value(_v) {}
deba@2126: 	};
deba@2126: 
deba@2126: 	void constraints() {
deba@2126: 	  checkConcept<Base, _Graph>();
deba@2126: 	  { // int map test
deba@2126: 	    typedef typename _Graph::template NodeMap<int> IntNodeMap;
deba@2126: 	    checkConcept<GraphMap<_Graph, typename _Graph::Node, int>, 
deba@2126: 	      IntNodeMap >();
deba@2126: 	  } { // bool map test
deba@2126: 	    typedef typename _Graph::template NodeMap<bool> BoolNodeMap;
deba@2126: 	    checkConcept<GraphMap<_Graph, typename _Graph::Node, bool>,
deba@2126: 	      BoolNodeMap >();
deba@2126: 	  } { // Dummy map test
deba@2126: 	    typedef typename _Graph::template NodeMap<Dummy> DummyNodeMap;
deba@2126: 	    checkConcept<GraphMap<_Graph, typename _Graph::Node, Dummy>,
deba@2126: 	      DummyNodeMap >();
deba@2126: 	  } 
deba@2126: 
deba@2126: 	  { // int map test
deba@2126: 	    typedef typename _Graph::template EdgeMap<int> IntEdgeMap;
deba@2126: 	    checkConcept<GraphMap<_Graph, typename _Graph::Edge, int>,
deba@2126: 	      IntEdgeMap >();
deba@2126: 	  } { // bool map test
deba@2126: 	    typedef typename _Graph::template EdgeMap<bool> BoolEdgeMap;
deba@2126: 	    checkConcept<GraphMap<_Graph, typename _Graph::Edge, bool>,
deba@2126: 	      BoolEdgeMap >();
deba@2126: 	  } { // Dummy map test
deba@2126: 	    typedef typename _Graph::template EdgeMap<Dummy> DummyEdgeMap;
deba@2126: 	    checkConcept<GraphMap<_Graph, typename _Graph::Edge, Dummy>, 
deba@2126: 	      DummyEdgeMap >();
deba@2126: 	  } 
deba@2126: 	}
deba@2126: 
deba@2126: 	_Graph& graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty mappable base graph class.
deba@2126:     ///
deba@2126:     /// This class provides beside the core graph features
deba@2126:     /// map interface for the graph structure.
deba@2126:     /// This concept is part of the UGraph concept.
deba@2126:     template <typename _Base = BaseUGraphComponent>
deba@2126:     class MappableUGraphComponent : public MappableGraphComponent<_Base>  {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef _Base Base;
deba@2126:       typedef typename Base::UEdge UEdge;
deba@2126: 
deba@2126:       typedef MappableUGraphComponent Graph;
deba@2126: 
deba@2126:       /// \brief ReadWrite map of the uedges.
deba@2126:       ///
deba@2126:       /// ReadWrite map of the uedges.
deba@2126:       ///
deba@2126:       template <typename Value>
deba@2126:       class UEdgeMap : public GraphMap<Graph, UEdge, Value> {  
deba@2126:       public:
deba@2126:         typedef GraphMap<Graph, UEdge, Value> Parent;
deba@2126: 
deba@2126: 	/// \brief Construct a new map.
deba@2126: 	///
deba@2126: 	/// Construct a new map for the graph.
deba@2126: 	/// \todo call the right parent class constructor
deba@2126: 	explicit UEdgeMap(const Graph& graph) : Parent(graph) {}
deba@2126: 
deba@2126: 	/// \brief Construct a new map with default value.
deba@2126: 	///
deba@2126: 	/// Construct a new map for the graph and initalise the values.
deba@2126: 	UEdgeMap(const Graph& graph, const Value& value)
deba@2126:           : Parent(graph, value) {}
deba@2126: 
deba@2126: 	/// \brief Copy constructor.
deba@2126: 	///
deba@2126: 	/// Copy Constructor.
deba@2126: 	UEdgeMap(const UEdgeMap& nm) : Parent(nm) {}
deba@2126: 
deba@2126: 	/// \brief Assign operator.
deba@2126: 	///
deba@2126: 	/// Assign operator.
deba@2126:         template <typename CMap>
deba@2126:         UEdgeMap& operator=(const CMap&) { 
deba@2126:           checkConcept<ReadMap<UEdge, Value>, CMap>();
deba@2126:           return *this;
deba@2126:         }
deba@2126: 
deba@2126:       };
deba@2126: 
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 
deba@2126: 	struct Dummy {
deba@2126: 	  int value;
deba@2126: 	  Dummy() : value(0) {}
deba@2126: 	  Dummy(int _v) : value(_v) {}
deba@2126: 	};
deba@2126: 
deba@2126: 	void constraints() {
deba@2126: 	  checkConcept<Base, _Graph>();
deba@2126: 	  checkConcept<MappableGraphComponent<Base>, _Graph>();
deba@2126: 
deba@2126: 	  { // int map test
deba@2126: 	    typedef typename _Graph::template UEdgeMap<int> IntUEdgeMap;
deba@2126: 	    checkConcept<GraphMap<_Graph, typename _Graph::UEdge, int>,
deba@2126: 	      IntUEdgeMap >();
deba@2126: 	  } { // bool map test
deba@2126: 	    typedef typename _Graph::template UEdgeMap<bool> BoolUEdgeMap;
deba@2126: 	    checkConcept<GraphMap<_Graph, typename _Graph::UEdge, bool>,
deba@2126: 	      BoolUEdgeMap >();
deba@2126: 	  } { // Dummy map test
deba@2126: 	    typedef typename _Graph::template UEdgeMap<Dummy> DummyUEdgeMap;
deba@2126: 	    checkConcept<GraphMap<_Graph, typename _Graph::UEdge, Dummy>, 
deba@2126: 	      DummyUEdgeMap >();
deba@2126: 	  } 
deba@2126: 	}
deba@2126: 
deba@2126: 	_Graph& graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126: 
deba@2126:     /// \brief An empty extendable graph class.
deba@2126:     ///
deba@2126:     /// This class provides beside the core graph features graph
deba@2126:     /// extendable interface for the graph structure.  The main
deba@2126:     /// difference between the base and this interface is that the
deba@2126:     /// graph alterations should handled already on this level.
deba@2126:     template <typename _Base = BaseGraphComponent>
deba@2126:     class ExtendableGraphComponent : public _Base {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef typename _Base::Node Node;
deba@2126:       typedef typename _Base::Edge Edge;
deba@2126: 
deba@2126:       /// \brief Adds a new node to the graph.
deba@2126:       ///
deba@2126:       /// Adds a new node to the graph.
deba@2126:       ///
deba@2126:       Node addNode() {
deba@2126: 	return INVALID;
deba@2126:       }
deba@2126:     
deba@2126:       /// \brief Adds a new edge connects the given two nodes.
deba@2126:       ///
deba@2126:       /// Adds a new edge connects the the given two nodes.
deba@2126:       Edge addEdge(const Node&, const Node&) {
deba@2126: 	return INVALID;
deba@2126:       }
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  typename _Graph::Node node_a, node_b;
deba@2126: 	  node_a = graph.addNode();
deba@2126: 	  node_b = graph.addNode();
deba@2126: 	  typename _Graph::Edge edge;
deba@2126: 	  edge = graph.addEdge(node_a, node_b);
deba@2126: 	}
deba@2126: 
deba@2126: 	_Graph& graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty extendable base undirected graph class.
deba@2126:     ///
deba@2126:     /// This class provides beside the core undirected graph features
deba@2126:     /// core undircted graph extend interface for the graph structure.
deba@2126:     /// The main difference between the base and this interface is
deba@2126:     /// that the graph alterations should handled already on this
deba@2126:     /// level.
deba@2126:     template <typename _Base = BaseUGraphComponent>
deba@2126:     class ExtendableUGraphComponent : public _Base {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef typename _Base::Node Node;
deba@2126:       typedef typename _Base::UEdge UEdge;
deba@2126: 
deba@2126:       /// \brief Adds a new node to the graph.
deba@2126:       ///
deba@2126:       /// Adds a new node to the graph.
deba@2126:       ///
deba@2126:       Node addNode() {
deba@2126: 	return INVALID;
deba@2126:       }
deba@2126:     
deba@2126:       /// \brief Adds a new edge connects the given two nodes.
deba@2126:       ///
deba@2126:       /// Adds a new edge connects the the given two nodes.
deba@2126:       UEdge addEdge(const Node&, const Node&) {
deba@2126: 	return INVALID;
deba@2126:       }
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  typename _Graph::Node node_a, node_b;
deba@2126: 	  node_a = graph.addNode();
deba@2126: 	  node_b = graph.addNode();
deba@2126: 	  typename _Graph::UEdge uedge;
deba@2126: 	  uedge = graph.addUEdge(node_a, node_b);
deba@2126: 	}
deba@2126: 
deba@2126: 	_Graph& graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty erasable graph class.
deba@2126:     ///  
deba@2126:     /// This class provides beside the core graph features core erase
deba@2126:     /// functions for the graph structure. The main difference between
deba@2126:     /// the base and this interface is that the graph alterations
deba@2126:     /// should handled already on this level.
deba@2126:     template <typename _Base = BaseGraphComponent>
deba@2126:     class ErasableGraphComponent : public _Base {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef _Base Base;
deba@2126:       typedef typename Base::Node Node;
deba@2126:       typedef typename Base::Edge Edge;
deba@2126: 
deba@2126:       /// \brief Erase a node from the graph.
deba@2126:       ///
deba@2126:       /// Erase a node from the graph. This function should 
deba@2126:       /// erase all edges connecting to the node.
deba@2126:       void erase(const Node&) {}    
deba@2126: 
deba@2126:       /// \brief Erase an edge from the graph.
deba@2126:       ///
deba@2126:       /// Erase an edge from the graph.
deba@2126:       ///
deba@2126:       void erase(const Edge&) {}
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  typename _Graph::Node node;
deba@2126: 	  graph.erase(node);
deba@2126: 	  typename _Graph::Edge edge;
deba@2126: 	  graph.erase(edge);
deba@2126: 	}
deba@2126: 
deba@2126: 	_Graph& graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty erasable base undirected graph class.
deba@2126:     ///  
deba@2126:     /// This class provides beside the core undirected graph features
deba@2126:     /// core erase functions for the undirceted graph structure. The
deba@2126:     /// main difference between the base and this interface is that
deba@2126:     /// the graph alterations should handled already on this level.
deba@2126:     template <typename _Base = BaseUGraphComponent>
deba@2126:     class ErasableUGraphComponent : public _Base {
deba@2126:     public:
deba@2126: 
deba@2126:       typedef _Base Base;
deba@2126:       typedef typename Base::Node Node;
deba@2126:       typedef typename Base::UEdge UEdge;
deba@2126: 
deba@2126:       /// \brief Erase a node from the graph.
deba@2126:       ///
deba@2126:       /// Erase a node from the graph. This function should erase
deba@2126:       /// edges connecting to the node.
deba@2126:       void erase(const Node&) {}    
deba@2126: 
deba@2126:       /// \brief Erase an edge from the graph.
deba@2126:       ///
deba@2126:       /// Erase an edge from the graph.
deba@2126:       ///
deba@2126:       void erase(const UEdge&) {}
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  typename _Graph::Node node;
deba@2126: 	  graph.erase(node);
deba@2126: 	  typename _Graph::Edge edge;
deba@2126: 	  graph.erase(edge);
deba@2126: 	}
deba@2126: 
deba@2126: 	_Graph& graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty clearable base graph class.
deba@2126:     ///
deba@2126:     /// This class provides beside the core graph features core clear
deba@2126:     /// functions for the graph structure. The main difference between
deba@2126:     /// the base and this interface is that the graph alterations
deba@2126:     /// should handled already on this level.
deba@2126:     template <typename _Base = BaseGraphComponent>
deba@2126:     class ClearableGraphComponent : public _Base {
deba@2126:     public:
deba@2126: 
deba@2126:       /// \brief Erase all nodes and edges from the graph.
deba@2126:       ///
deba@2126:       /// Erase all nodes and edges from the graph.
deba@2126:       ///
deba@2126:       void clear() {}    
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  graph.clear();
deba@2126: 	}
deba@2126: 
deba@2126: 	_Graph graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:     /// \brief An empty clearable base undirected graph class.
deba@2126:     ///
deba@2126:     /// This class provides beside the core undirected graph features
deba@2126:     /// core clear functions for the undirected graph structure. The
deba@2126:     /// main difference between the base and this interface is that
deba@2126:     /// the graph alterations should handled already on this level.
deba@2126:     template <typename _Base = BaseUGraphComponent>
deba@2126:     class ClearableUGraphComponent : public _Base {
deba@2126:     public:
deba@2126: 
deba@2126:       /// \brief Erase all nodes and undirected edges from the graph.
deba@2126:       ///
deba@2126:       /// Erase all nodes and undirected edges from the graph.
deba@2126:       ///
deba@2126:       void clear() {}    
deba@2126: 
deba@2126:       template <typename _Graph>
deba@2126:       struct Constraints {
deba@2126: 	void constraints() {
deba@2126: 	  graph.clear();
deba@2126: 	}
deba@2126: 
deba@2126: 	_Graph graph;
deba@2126:       };
deba@2126:     };
deba@2126: 
deba@2126:   }
deba@2126: 
deba@2126: }
deba@2126: 
deba@2126: #endif