diff -r aa19ca32d9b0 -r ca95f8b5c931 src/lemon/concept/graph_component.h
--- a/src/lemon/concept/graph_component.h	Sat Nov 13 17:47:44 2004 +0000
+++ b/src/lemon/concept/graph_component.h	Sat Nov 13 21:37:54 2004 +0000
@@ -37,90 +37,64 @@
     /// base class, this is a template. For Node you should instantiate it
     /// with character 'n' and for Edge with 'e'.
 
-    template<char Ch>
+    template<char _selector>
     class GraphItem {
     public:
+      /// Default constructor.
+      
+      /// @warning The default constructor sets the item
+      /// to an undefined value.
       GraphItem() {}
+      /// Copy constructor.
+      
+      /// Copy constructor.
+      ///
+      GraphItem(GraphItem const&) {}
+      /// Invalid constructor \& conversion.
+
+      /// This constructor initializes the item to be invalid.
+      /// \sa Invalid for more details.
       GraphItem(Invalid) {}
+      /// Assign operator for nodes.
 
-      // We explicitely list these:
-      GraphItem(GraphItem const&) {}
+      /// The nodes are assignable. 
+      ///
       GraphItem& operator=(GraphItem const&) { return *this; }
-
+      /// Equality operator.
+      
+      /// Two iterators are equal if and only if they represents the
+      /// same node in the graph or both are invalid.
       bool operator==(GraphItem) const { return false; }
+      /// Inequality operator.
+	
+      /// \sa operator==(const Node& n)
+      ///
       bool operator!=(GraphItem) const { return false; }
 
       // Technical requirement. Do we really need this?
-      bool operator<(GraphItem) const { return false; }
+      //      bool operator<(GraphItem) const { return false; }
+
+
+      template<typename _GraphItem>
+      struct Constraints {
+	void constraints() {
+	  _GraphItem i1;
+	  _GraphItem i2 = i1;
+	  _GraphItem i3 = INVALID;
+	  
+	  i1 = i2 = i3;
+
+	  bool b;
+	  //	  b = (ia == ib) && (ia != ib) && (ia < ib);
+	  b = (ia == ib) && (ia != ib);
+	  b = (ia == INVALID) && (ib != INVALID);
+	}
+
+	const _GraphItem &ia;
+	const _GraphItem &ib;
+      };
     };
 
-
-    template<typename GI>
-    struct GraphItemConcept {
-      void constraints() {
-	GI i1;
-	GI i2 = i1;
-	GI i3 = INVALID;
-	
-	i1 = i2 = i3;
-
-	bool b;
-	b = (ia == ib) && (ia != ib) && (ia < ib);
-	b = (ia == INVALID) && (ib != INVALID);
-      }
-
-      const GI &ia;
-      const GI &ib;
-    };
-
-
-    template<typename Iter, typename Graph, typename BaseItem>
-    struct GraphIteratorConcept {
-      void constraints() {
-	function_requires< GraphItemConcept<Iter> >();
-	Iter it1(g);
-
-	/// \todo Do we need NodeIt(Node) kind of constructor?
-	//	Iter it2(bj);
-	Iter it2;
-
-	it2 = ++it1;
-	++it2 = it1;
-	++(++it1);
-	/// \bug This should be: is_base_and_derived<BaseItem, Iter>
-	BaseItem bi = it1;
-	bi = it2;
-      }
-
-      BaseItem bj;
-      Graph g;
-    };
-
-    template<typename Iter, typename Graph>
-    struct GraphIncIteratorConcept {
-      typedef typename Graph::Node Node;
-      typedef typename Graph::Edge Edge;
-      void constraints() {
-	function_requires< GraphItemConcept<Iter> >();
-	Iter it1(graph, node);
-	/// \todo Do we need OutEdgeIt(Edge) kind of constructor?
-	//	Iter it2(edge);
-	Iter it2;
-
-	it2 = ++it1;
-	++it2 = it1;
-	++(++it1);
-	Edge e = it1;
-	e = it2;
-      }
-
-      Edge edge;
-      Node node;
-      Graph graph;
-    };
-
-
-
     /// An empty base graph class.
   
     /// This class provides the minimal set of features needed for a graph
@@ -139,108 +113,13 @@
 
       /// This class represents the Nodes of the graph. 
       ///
-      class Node {
-      public:
-
-	/// Default constructor.
-
-	/// @warning The default constructor sets the iterator
-	/// to an undefined value.
-
-	Node() {}
-	/// Copy constructor.
-
-	/// Copy constructor.
-	///
-	Node(const Node&) {}
-
-	/// Invalid constructor \& conversion.
-
-	/// This constructor initializes the iterator to be invalid.
-	/// \sa Invalid for more details.
-	Node(Invalid) {}
-
-
-	/// Assign operator for nodes.
-
-	/// The nodes are assignable. 
-	///
-	Node& operator=(const Node&) { return *this;}
-
-	/// Equality operator.
-
-	/// Two iterators are equal if and only if they represents the
-	/// same node in the graph or both are invalid.
-	bool operator==(const Node&) const { return true;}
-
-
-	/// Inequality operator.
-	
-	/// \sa operator==(const Node& n)
-	///
-	bool operator!=(const Node&) const { return true;}
-
- 	/// Comparison operator.
-
-	/// This is a strict ordering between the nodes.
-	///
-	/// This ordering can be different from the iterating order of nodes.
-	/// \todo Possibly we don't need it.
-	bool operator<(const Node&) const { return true;}
-      };
+      typedef GraphItem<'n'> Node;
 
       /// Edge class of the graph.
 
       /// This class represents the Edges of the graph. 
       ///
-      class Edge {
-      public:
-
-	/// Default constructor.
-
-	/// @warning The default constructor sets the iterator
-	/// to an undefined value.
-
-	Edge() {}
-	/// Copy constructor.
-
-	/// Copy constructor.
-	///
-	Edge(const Edge&) {}
-
-	/// Invalid constructor \& conversion.
-
-	/// This constructor initializes the iterator to be invalid.
-	/// \sa Invalid for more details.
-	Edge(Invalid) {}
-
-	/// Assign operator for edges.
-
-	/// The edges are assignable. 
-	///
-	Edge& operator=(const Edge&) { return *this;}
-
-	/// Equality operator.
-
-	/// Two iterators are equal if and only if they represents the
-	/// same edge in the graph or both are invalid.
-	bool operator==(const Edge&) const { return true;}
-
-
-	/// Inequality operator.
-	
-	/// \sa operator==(const Edge& n)
-	///
-	bool operator!=(const Edge&) const { return true;}
-
- 	/// Comparison operator.
-
-	/// This is a strict ordering between the edges.
-	///
-	/// This ordering can be different from the iterating order of edges.
-	/// \todo Possibly we don't need it.
-	bool operator<(const Edge&) const { return true;}
-      };
+      typedef GraphItem<'e'> Edge;
 
       ///Gives back the target node of an edge.
 
@@ -253,31 +132,26 @@
       ///Gives back the source node of an edge.
       ///
       Node source(const Edge&) const { return INVALID;}
-    };
 
 
-    /// Concept check structure for BaseGraph.
-
-    /// Concept check structure for BaseGraph.
-    ///
-
-    template <typename Graph>
-    struct BaseGraphComponentConcept {
-      typedef typename Graph::Node Node;
-      typedef typename Graph::Edge Edge;
+      template <typename _Graph>
+      struct Constraints {
+	typedef typename _Graph::Node Node;
+	typedef typename _Graph::Edge Edge;
       
-      void constraints() {
-	function_requires< GraphItemConcept<Node> >();
-	function_requires< GraphItemConcept<Edge> >();
-	{
-	  Node n;
-	  Edge e;
-	  n = graph.source(e);
-	  n = graph.target(e);
-	}      
-      }
+	void constraints() {
+	  checkConcept<GraphItem<'n'>, Node>();
+	  checkConcept<GraphItem<'e'>, Edge>();
+	  {
+	    Node n;
+	    Edge e;
+	    n = graph.source(e);
+	    n = graph.target(e);
+	  }      
+	}
       
-      const Graph& graph;
+	const _Graph& graph;
+      };
     };
 
     /// An empty iterable base graph class.
@@ -340,39 +214,35 @@
       /// Gives back the next of the Edges start from the given Node.
       ///     
       void nextOut(Edge&) const {}
-    };
 
 
-    /// Concept check structure for IterableBaseGraph.
+      template <typename _Graph>
+      struct Constraints {
+      
+	void constraints() {
+	  checkConcept< BaseGraphComponent, _Graph >();
+	  typename _Graph::Node node;      
+	  typename _Graph::Edge edge;
+	  {
+	    graph.first(node);
+	    graph.next(node);
+	  }
+	  {
+	    graph.first(edge);
+	    graph.next(edge);
+	  }
+	  {
+	    graph.firstIn(edge, node);
+	    graph.nextIn(edge);
+	  }
+	  {
+	    graph.firstOut(edge, node);
+	    graph.nextOut(edge);
+	  }
+	}
 
-    /// Concept check structure for IterableBaseGraph.
-    ///
-    template <typename Graph>
-    struct BaseIterableGraphComponentConcept {
-      
-      void constraints() {
-	function_requires< BaseGraphComponentConcept<Graph> >();
-	typename Graph::Node node;      
-	typename Graph::Edge edge;
-	{
-	  graph.first(node);
-	  graph.next(node);
-	}
-	{
-	  graph.first(edge);
-	  graph.next(edge);
-	}
-	{
-	  graph.firstIn(edge, node);
-	  graph.nextIn(edge);
-	}
-	{
-	  graph.firstOut(edge, node);
-	  graph.nextOut(edge);
-	}
-      }
-
-      const Graph& graph;
+	const _Graph& graph;
+      };
     };
 
     /// An empty idable base graph class.
@@ -381,7 +251,6 @@
     /// core id functions for the graph structure.
     /// The most of the base graphs should be conform to this concept.
     /// The id's are unique and immutable.
-
     class IDableGraphComponent : virtual public BaseGraphComponent {
     public:
 
@@ -399,27 +268,22 @@
       /// Gives back an unique integer id for the Edge. 
       ///
       int id(const Edge&) const { return -1;}
-    };
 
+      template <typename _Graph>
+      struct Constraints {
 
-    /// Concept check structure for IdableBaseGraph.
+	void constraints() {
+	  checkConcept< BaseGraphComponent, _Graph >();
+	  typename _Graph::Node node;
+	  int nid = graph.id(node);
+	  nid = graph.id(node);
+	  typename _Graph::Edge edge;
+	  int eid = graph.id(edge);
+	  eid = graph.id(edge);
+	}
 
-    /// Concept check structure for IdableBaseGraph.
-    ///
-    template <typename Graph>
-    struct IDableGraphComponentConcept {
-
-      void constraints() {
-	function_requires< BaseGraphComponentConcept<Graph> >();
-	typename Graph::Node node;
-	int nid = graph.id(node);
-	nid = graph.id(node);
-	typename Graph::Edge edge;
-	int eid = graph.id(edge);
-	eid = graph.id(edge);
-      }
-
-      const Graph& graph;
+	const _Graph& graph;
+      };
     };
 
 
@@ -443,24 +307,20 @@
       /// Gives back an integer greater or equal to the maximum Edge id. 
       ///
       int maxId(Edge = INVALID) const { return -1;}
-    };
 
-    /// Concept check structure for MaxIdableBaseGraph.
+      template <typename _Graph>
+      struct Constraints {
 
-    /// Concept check structure for MaxIdableBaseGraph.
-    ///
-    template <typename Graph>
-    struct MaxIDableGraphComponentConcept {
-
-      void constraints() {
-	function_requires< BaseGraphComponentConcept<Graph> >();
-	int nid = graph.maxId(typename Graph::Node());
-	ignore_unused_variable_warning(nid);
-	int eid = graph.maxId(typename Graph::Edge());
-	ignore_unused_variable_warning(eid);
-      }
-
-      const Graph& graph;
+	void constraints() {
+	  checkConcept<BaseGraphComponent, _Graph>();
+	  int nid = graph.maxId(typename _Graph::Node());
+	  ignore_unused_variable_warning(nid);
+	  int eid = graph.maxId(typename _Graph::Edge());
+	  ignore_unused_variable_warning(eid);
+	}
+      
+	const _Graph& graph;
+      };
     };
 
     /// An empty extendable base graph class.
@@ -490,23 +350,18 @@
 	return INVALID;
       }
 
-    };
+      template <typename _Graph>
+      struct Constraints {
+	void constraints() {
+	  checkConcept<BaseGraphComponent, _Graph >();
+	  typename _Graph::Node node_a, node_b;
+	  node_a = graph.addNode();
+	  typename _Graph::Edge edge;
+	  edge = graph.addEdge(node_a, node_b);
+	}
 
-    /// Concept check structure for ExtendableBaseGraph.
-
-    /// Concept check structure for ExtendableBaseGraph.
-    ///
-    template <typename Graph>
-    struct BaseExtendableGraphComponentConcept {
-      void constraints() {
-	function_requires< BaseGraphComponentConcept<Graph> >();
-	typename Graph::Node node_a, node_b;
-	node_a = graph.addNode();
-	typename Graph::Edge edge;
-	edge = graph.addEdge(node_a, node_b);
-      }
-
-      Graph& graph;
+	_Graph& graph;
+      };
     };
 
     /// An empty erasable base graph class.
@@ -532,23 +387,18 @@
       ///
       void erase(const Edge&) {}
 
-    };
+      template <typename _Graph>
+      struct Constraints {
+	void constraints() {
+	  checkConcept<BaseGraphComponent, _Graph>();
+	  typename _Graph::Node node;
+	  graph.erase(node);
+	  typename _Graph::Edge edge;
+	  graph.erase(edge);
+	}
 
-    /// Concept check structure for ErasableBaseGraph.
-
-    /// Concept check structure for ErasableBaseGraph.
-    ///
-    template <typename Graph>
-    struct BaseErasableGraphComponentConcept {
-      void constraints() {
-	function_requires< BaseGraphComponentConcept<Graph> >();
-	typename Graph::Node node;
-	graph.erase(node);
-	typename Graph::Edge edge;
-	graph.erase(edge);
-      }
-
-      Graph& graph;
+	_Graph& graph;
+      };
     };
 
     /// An empty clearable base graph class.
@@ -564,25 +414,172 @@
       /// Erase all the Nodes and Edges from the graph.
       ///
       void clear() {}    
+
+      template <typename _Graph>
+      struct Constraints {
+	void constraints() {
+	  checkConcept< BaseGraphComponent, _Graph>();
+	  graph.clear();
+	}
+
+	_Graph& graph;
+      };
     };
 
-    /// Concept check function for ErasableBaseGraph.
 
-    /// Concept check function for ErasableBaseGraph.
+    /// Skeleton class for graph NodeIt and EdgeIt
+
+    /// Skeleton class for graph NodeIt and EdgeIt.
     ///
-    template <typename Graph>
-    struct BaseClearableGraphComponentConcept {
-      void constraints() {
-	function_requires< BaseGraphComponentConcept<Graph> >();
-	graph.clear();
-      }
+    template <typename _Graph, typename _Item>
+    class GraphIterator : public _Item {
+    public:
+      /// \todo Don't we need the Item type as typedef?
 
-      Graph& graph;
+      /// Default constructor.
+      
+      /// @warning The default constructor sets the iterator
+      /// to an undefined value.
+      GraphIterator() {}
+      /// Copy constructor.
+      
+      /// Copy constructor.
+      ///
+      GraphIterator(GraphIterator const&) {}
+      /// Sets the iterator to the first item.
+      
+      /// Sets the iterator to the first item of \c the graph.
+      ///
+      explicit GraphIterator(const _Graph&) {}
+      /// Invalid constructor \& conversion.
+
+      /// This constructor initializes the item to be invalid.
+      /// \sa Invalid for more details.
+      GraphIterator(Invalid) {}
+      /// Assign operator for items.
+
+      /// The items are assignable. 
+      ///
+      GraphIterator& operator=(GraphIterator const&) { return *this; }      
+      /// Next item.
+
+      /// Assign the iterator to the next item.
+      ///
+      GraphIterator& operator++() { return *this; }
+      //	Node operator*() const { return INVALID; }
+      /// Equality operator
+
+      /// Two iterators are equal if and only if they point to the
+      /// same object or both are invalid.
+      bool operator==(const GraphIterator&) const { return true;}
+      /// Inequality operator
+	
+      /// \sa operator==(Node n)
+      ///
+      bool operator!=(const GraphIterator&) const { return true;}
+      
+      template<typename _GraphIterator>
+      struct Constraints {
+	void constraints() {
+	  //	  checkConcept< Item, _GraphIterator >();
+	  _GraphIterator it1(g);
+	
+	  /// \todo Do we need NodeIt(Node) kind of constructor?
+	  //	_GraphIterator it2(bj);
+	  _GraphIterator it2;
+
+	  it2 = ++it1;
+	  ++it2 = it1;
+	  ++(++it1);
+	  /// \bug This should be: is_base_and_derived<BaseItem, _GraphIterator>
+	  _Item bi = it1;
+	  bi = it2;
+	}
+	_Graph& g;
+      };
     };
 
+    /// Skeleton class for graph InEdgeIt and OutEdgeIt
 
-    class IterableGraphComponent :
-      virtual public BaseIterableGraphComponent {
+    /// \note Because InEdgeIt and OutEdgeIt may not inherit from the same
+    /// base class, the _selector is a additional template parameter. For 
+    /// InEdgeIt you should instantiate it with character 'i' and for 
+    /// OutEdgeIt with 'o'.
+    /// \todo check the name of the concept GraphIncEdgeIterator
+    template <typename _Graph, char _selector>
+    class GraphIncEdgeIterator : public _Graph::Edge {
+    public:
+      /// Default constructor.
+      
+      /// @warning The default constructor sets the iterator
+      /// to an undefined value.
+      GraphIncEdgeIterator() {}
+      /// Copy constructor.
+      
+      /// Copy constructor.
+      ///
+      GraphIncEdgeIterator(GraphIncEdgeIterator const&) {}
+      /// Sets the iterator to the first edge incoming into or outgoing from the node.
+      
+      /// Sets the iterator to the first edge incoming into or outgoing from the node.
+      ///
+      explicit GraphIncEdgeIterator(const _Graph&, const typename _Graph::Node&) {}
+      /// Invalid constructor \& conversion.
+
+      /// This constructor initializes the item to be invalid.
+      /// \sa Invalid for more details.
+      GraphIncEdgeIterator(Invalid) {}
+      /// Assign operator for nodes.
+
+      /// The nodes are assignable. 
+      ///
+      GraphIncEdgeIterator& operator=(GraphIncEdgeIterator const&) { return *this; }      
+      /// Next edge.
+
+      /// Assign the iterator to the next node.
+      ///
+      GraphIncEdgeIterator& operator++() { return *this; }
+      //	Node operator*() const { return INVALID; }
+      /// Equality operator
+
+      /// Two iterators are equal if and only if they point to the
+      /// same object or both are invalid.
+      bool operator==(const GraphIncEdgeIterator&) const { return true;}
+      /// Inequality operator
+	
+      /// \sa operator==(Node n)
+      ///
+      bool operator!=(const GraphIncEdgeIterator&) const { return true;}
+
+      template <typename _GraphIncEdgeIterator>
+      struct Constraints {
+	typedef typename _Graph::Node Node;
+	typedef typename _Graph::Edge Edge;
+	void constraints() {
+	  checkConcept<GraphItem<'e'>, _GraphIncEdgeIterator>();
+	  _GraphIncEdgeIterator it1(graph, node);
+	  /// \todo Do we need OutEdgeIt(Edge) kind of constructor?
+	  //	_GraphIncEdgeIterator it2(edge);
+	  _GraphIncEdgeIterator it2;
+
+	  it2 = ++it1;
+	  ++it2 = it1;
+	  ++(++it1);
+	  Edge e = it1;
+	  e = it2;
+	}
+
+	Edge& edge;
+	Node& node;
+	_Graph& graph;
+      };
+    };
+    /// An empty iterable base graph class.
+  
+    /// This class provides beside the core graph features
+    /// iterator based iterable interface for the graph structure.
+    /// This concept is part of the StaticGraphConcept.
+    class IterableGraphComponent : virtual public BaseGraphComponent {
 
     public:
     
@@ -591,84 +588,80 @@
       typedef BaseGraphComponent::Node Node;
       typedef BaseGraphComponent::Edge Edge;
 
-      class NodeIt : public Node {
-      public:
-	NodeIt() {}
-	NodeIt(Invalid) {}
-	// explicit NodeIt(Node) {}
-	explicit NodeIt(const Graph&) {}
+      /// This iterator goes through each node.
 
-	NodeIt& operator++() { return *this; }
-	//	Node operator*() const { return INVALID; }
+      /// This iterator goes through each node.
+      ///
+      typedef GraphIterator<Graph, Node> NodeIt;
+      /// This iterator goes through each node.
 
-	bool operator==(const NodeIt&) const { return true;}
-	bool operator!=(const NodeIt&) const { return true;}
-      };
+      /// This iterator goes through each node.
+      ///
+      typedef GraphIterator<Graph, Edge> EdgeIt;
+      /// This iterator goes trough the incoming edges of a node.
 
-      class EdgeIt : public Edge {
-      public:
-	EdgeIt() {}
-	EdgeIt(Invalid) {}
-	// explicit EdgeIt(Edge) {}
-	explicit EdgeIt(const Graph&) {}
+      /// This iterator goes trough the \e inccoming edges of a certain node
+      /// of a graph.
+      typedef GraphIncEdgeIterator<Graph, 'i'> InEdgeIt;
+      /// This iterator goes trough the outgoing edges of a node.
 
-	EdgeIt& operator++() { return *this; }
-	//	Edge operator*() const { return INVALID; }
+      /// This iterator goes trough the \e outgoing edges of a certain node
+      /// of a graph.
+      typedef GraphIncEdgeIterator<Graph, 'o'> OutEdgeIt;
+    };
+    
+    template <typename _Graph> 
+    struct Constraints {
+      void constraints() {
+  	checkConcept< BaseGraphComponent, _Graph>();
 
-	bool operator==(const EdgeIt&) const { return true;}
-	bool operator!=(const EdgeIt&) const { return true;}
-      };
+	checkConcept<GraphIterator<_Graph, typename _Graph::Edge>, typename _Graph::EdgeIt >();
+	checkConcept<GraphIterator<_Graph, typename _Graph::Node>, typename _Graph::NodeIt >();
+	checkConcept<GraphIncEdgeIterator<_Graph, 'i'>, typename _Graph::InEdgeIt >();
+	checkConcept<GraphIncEdgeIterator<_Graph, 'o'>, typename _Graph::OutEdgeIt >();
+      }
+    };
 
-      class InEdgeIt : public Edge {
-      public:
-	InEdgeIt() {}
-	InEdgeIt(Invalid) {}
-	// explicit InEdgeIt(Edge) {}
-	explicit InEdgeIt(const Graph&, const Node&) {}
 
-	InEdgeIt& operator++() { return *this; }
-	//	Edge operator*() const { return INVALID; }
+    template <typename Graph, typename Item, typename _Value>
+    class GraphMap : public ReadWriteMap<Item, _Value> {
+    protected:      
+      GraphMap() {}
+    public:
+      explicit GraphMap(const Graph&) {}
+      GraphMap(const Graph&, const _Value&) {}
+      GraphMap(const GraphMap&) {}
+      
+      GraphMap& operator=(const GraphMap&) { return *this;}
 
-	bool operator==(const InEdgeIt&) const { return true;}
-	bool operator!=(const InEdgeIt&) const { return true;}
-      };
+      template<typename _Map>
+      struct Constraints {
+	void constraints() {
+	  checkConcept<ReadWriteMap<Item, _Value>, _Map >();
+	  // Construction with a graph parameter
+	  _Map a(g);
+	  // Constructor with a graph and a default value parameter
+	  _Map a2(g,t);
+	  // Copy constructor. Do we need it?
+	  _Map b=c;
+	  // Copy operator. Do we need it?
+	  a=b;
 
-      class OutEdgeIt : public Edge {
-      public:
-	OutEdgeIt() {}
-	OutEdgeIt(Invalid) {}
-	// explicit OutEdgeIt(Edge) {}
-	explicit OutEdgeIt(const Graph&, const Node&) {}
+	  ignore_unused_variable_warning(a2);
+	}
 
-	OutEdgeIt& operator++() { return *this; }
-	//	Edge operator*() const { return INVALID; }
-
-	bool operator==(const OutEdgeIt&) const { return true;}
-	bool operator!=(const OutEdgeIt&) const { return true;}
+	const _Map &c;
+	const Graph &g;
+	const typename GraphMap::Value &t;
       };
 
     };
-    
-    template <typename Graph> 
-    struct IterableGraphComponentConcept {
-      void constraints() {
-  	function_requires< BaseIterableGraphComponentConcept<Graph> >();
 
-	typedef typename Graph::Node Node;
-	typedef typename Graph::NodeIt NodeIt;
-	typedef typename Graph::Edge Edge;
-	typedef typename Graph::EdgeIt EdgeIt;
-	typedef typename Graph::InEdgeIt InEdgeIt;
-	typedef typename Graph::OutEdgeIt OutEdgeIt;
+    /// An empty mappable base graph class.
   
-	function_requires< GraphIteratorConcept<NodeIt, Graph, Node> >();
-	function_requires< GraphIteratorConcept<EdgeIt, Graph, Edge> >();
-	function_requires< GraphIncIteratorConcept<OutEdgeIt, Graph> >();
-	function_requires< GraphIncIteratorConcept<InEdgeIt, Graph> >();
-      }
-    };
-
-
+    /// This class provides beside the core graph features
+    /// map interface for the graph structure.
+    /// This concept is part of the StaticGraphConcept.
     class MappableGraphComponent : virtual public BaseGraphComponent {
     public:
 
@@ -677,65 +670,78 @@
       typedef BaseGraphComponent::Node Node;
       typedef BaseGraphComponent::Edge Edge;
 
+      /// ReadWrite map of the nodes.
+    
+      /// ReadWrite map of the nodes.
+      ///
       template <typename _Value>
-      class NodeMap : public ReferenceMap<Node, _Value> {
+      class NodeMap : public GraphMap<Graph, Node, _Value> {
+      private:
+	NodeMap();
       public:
-	NodeMap(const Graph&) {}
+	// \todo call the right parent class constructor
+	explicit NodeMap(const Graph&) {}
 	NodeMap(const Graph&, const _Value&) {}
 	NodeMap(const NodeMap&) {}
 
 	NodeMap& operator=(const NodeMap&) { return *this;}
-	
+
       };
 
+      /// ReadWrite map of the edges.
+    
+      /// ReadWrite map of the edges.
+      ///
       template <typename _Value>
-      class EdgeMap : public ReferenceMap<Edge, _Value> {
+      class EdgeMap : public GraphMap<Graph, Edge, _Value> {
+      private:
+	EdgeMap();
       public:
-	EdgeMap(const Graph&) {}
+	// \todo call the right parent class constructor
+	explicit EdgeMap(const Graph&) {}
 	EdgeMap(const Graph&, const _Value&) {}
 	EdgeMap(const EdgeMap&) {}
 
 	EdgeMap& operator=(const EdgeMap&) { return *this;}
-	
+
       };
 
-    };
+      template <typename _Graph>
+      struct Constraints {
 
-    template <typename Graph>
-    struct MappableGraphComponentConcept {
+	struct Type {
+	  int value;
+	  Type() : value(0) {}
+	  Type(int _v) : value(_v) {}
+	};
 
-      struct Type {
-	int value;
-	Type() : value(0) {}
-	Type(int _v) : value(_v) {}
+	void constraints() {
+	  checkConcept<BaseGraphComponent, _Graph>();
+	  { // int map test
+	    typedef typename _Graph::template NodeMap<int> IntNodeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::Node, int>, IntNodeMap >();
+	  } { // bool map test
+	    typedef typename _Graph::template NodeMap<bool> BoolNodeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::Node, bool>, BoolNodeMap >();
+	  } { // Type map test
+	    typedef typename _Graph::template NodeMap<Type> TypeNodeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::Node, Type>, TypeNodeMap >();
+	  } 
+
+	  { // int map test
+	    typedef typename _Graph::template EdgeMap<int> IntEdgeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::Edge, int>, IntEdgeMap >();
+	  } { // bool map test
+	    typedef typename _Graph::template EdgeMap<bool> BoolEdgeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::Edge, bool>, BoolEdgeMap >();
+	  } { // Type map test
+	    typedef typename _Graph::template EdgeMap<Type> TypeEdgeMap;
+	    checkConcept<GraphMap<_Graph, typename _Graph::Edge, Type>, TypeEdgeMap >();
+	  } 
+	}
+
+	_Graph& graph;
       };
-
-      void constraints() {
-	function_requires< BaseGraphComponentConcept<Graph> >();
-	{ // int map test
-	  typedef typename Graph::template NodeMap<int> IntNodeMap;
-	  function_requires<GraphMapConcept<IntNodeMap,Graph> >();
-	} { // bool map test
-	  typedef typename Graph::template NodeMap<bool> BoolNodeMap;
-	  function_requires<GraphMapConcept<BoolNodeMap,Graph> >();
-	} { // Type map test
-	  typedef typename Graph::template NodeMap<Type> TypeNodeMap;
-	  function_requires<GraphMapConcept<TypeNodeMap,Graph> >();
-	} 
-
-	{ // int map test
-	  typedef typename Graph::template EdgeMap<int> IntEdgeMap;
-	  function_requires<GraphMapConcept<IntEdgeMap,Graph> >();
-	} { // bool map test
-	  typedef typename Graph::template EdgeMap<bool> BoolEdgeMap;
-	  function_requires<GraphMapConcept<BoolEdgeMap,Graph> >();
-	} { // Type map test
-	  typedef typename Graph::template EdgeMap<Type> TypeEdgeMap;
-	  function_requires<GraphMapConcept<TypeEdgeMap,Graph> >();
-	} 
-      }
-
-      Graph& graph;
     };
 
 
@@ -755,20 +761,18 @@
 	return INVALID;
       }
 
+      template <typename _Graph>
+      struct Constraints {
+	void constraints() {
+	  checkConcept<BaseGraphComponent, _Graph >();
+	  typename _Graph::Node node_a, node_b;
+	  node_a = graph.addNode();
+	  typename _Graph::Edge edge;
+	  edge = graph.addEdge(node_a, node_b);      
+	}
+	_Graph& graph;
+      };
     };
-
-    template <typename Graph>
-    struct ExtendableGraphComponentConcept {
-      void constraints() {
-	function_requires< BaseGraphComponentConcept<Graph> >();
-	typename Graph::Node node_a, node_b;
-	node_a = graph.addNode();
-	typename Graph::Edge edge;
-	edge = graph.addEdge(node_a, node_b);      
-      }
-      Graph& graph;
-    };
-
     class ErasableGraphComponent : virtual public BaseGraphComponent {
     public:
 
@@ -780,19 +784,18 @@
       void erase(const Node&) {}    
       void erase(const Edge&) {}
 
-    };
+      template <typename _Graph>
+      struct Constraints {
+	void constraints() {
+	  checkConcept<BaseGraphComponent, _Graph >();
+	  typename _Graph::Node node;
+	  graph.erase(node);
+	  typename _Graph::Edge edge;
+	  graph.erase(edge);      
+	}
 
-    template <typename Graph>
-    struct ErasableGraphComponentConcept {
-      void constraints() {
-	function_requires< BaseGraphComponentConcept<Graph> >();
-	typename Graph::Node node;
-	graph.erase(node);
-	typename Graph::Edge edge;
-	graph.erase(edge);      
-      }
-
-      Graph& graph;
+	_Graph& graph;
+      };
     };
 
     class ClearableGraphComponent : virtual public BaseGraphComponent {
@@ -805,15 +808,15 @@
 
       void clear() {}    
 
-    };
 
-    template <typename Graph>
-    struct ClearableGraphComponentConcept {
-      void constraints() {
-	function_requires< BaseGraphComponentConcept<Graph> >();
-	graph.clear();
-      }
-      Graph& graph;
+      template <typename _Graph>
+      struct ClearableGraphComponentConcept {
+	void constraints() {
+	  checkConcept< BaseGraphComponent, _Graph >();
+	  graph.clear();
+	}
+	_Graph& graph;
+      };
     };
 
   }