diff -r b5fb023cdb7b -r 0f1044b7a3af src/lemon/concept/graph_component.h
--- a/src/lemon/concept/graph_component.h	Wed Nov 10 21:59:59 2004 +0000
+++ b/src/lemon/concept/graph_component.h	Thu Nov 11 09:31:55 2004 +0000
@@ -161,6 +161,10 @@
 	Node(Invalid) {}
 
 
+	/// Assign operator for nodes.
+
+	/// The nodes are assignable. 
+	///
 	Node& operator=(const Node&) { return *this;}
 
 	/// Equality operator.
@@ -210,7 +214,10 @@
 	/// \sa Invalid for more details.
 	Edge(Invalid) {}
 
+	/// Assign operator for edges.
 
+	/// The edges are assignable. 
+	///
 	Edge& operator=(const Edge&) { return *this;}
 
 	/// Equality operator.
@@ -429,13 +436,13 @@
 
       /// Gives back an integer greater or equal to the maximum Node id. 
       ///
-      int maxEdgeId() const { return -1;}
+      int maxId(Node = INVALID) const { return -1;}
 
       /// Gives back an integer greater or equal to the maximum Edge id. 
 
       /// Gives back an integer greater or equal to the maximum Edge id. 
       ///
-      int maxNodeId() const { return -1;}
+      int maxId(Edge = INVALID) const { return -1;}
     };
 
     /// Concept check structure for MaxIdableBaseGraph.
@@ -447,9 +454,9 @@
 
       void constraints() {
 	function_requires< BaseGraphComponentConcept<Graph> >();
-	int nid = graph.maxEdgeId();
+	int nid = graph.maxId(typename Graph::Node());
 	ignore_unused_variable_warning(nid);
-	int eid = graph.maxNodeId();
+	int eid = graph.maxId(typename Graph::Edge());
 	ignore_unused_variable_warning(eid);
       }
 
@@ -662,52 +669,6 @@
     };
 
 
-    class IdMappableGraphComponent : virtual public BaseGraphComponent {
-
-      typedef IdMappableGraphComponent Graph;
-
-    public:
-
-      typedef BaseGraphComponent::Node Node;
-      typedef BaseGraphComponent::Edge Edge;
-
-      class NodeIdMap : public ReadMap<Node, int> {
-      public:
-	NodeIdMap(const Graph&) {}
-	int maxId() const { return -1;}
-      };
-
-      class EdgeIdMap : public ReadMap<Edge, int> {
-      public:
-	EdgeIdMap(const Graph&) {}
-	int maxId() const { return -1;}
-      };
-
-    };
-    
-    template <typename Graph>
-    struct IdMappableGraphComponentConcept {
-      void constraints() {	
-	function_requires< BaseGraphComponentConcept<Graph> >();
-	{
-	  typedef typename Graph::EdgeIdMap EdgeIdMap;
-	  function_requires<ReadMapConcept<EdgeIdMap> >();
-	  EdgeIdMap edge_map(graph);
-	  int n = edge_map.maxId();
-	  ignore_unused_variable_warning(n);
-	}
-	{
-	  typedef typename Graph::NodeIdMap NodeIdMap;
-	  function_requires<ReadMapConcept<NodeIdMap> >();
-	  NodeIdMap node_map(graph);
-	  int n = node_map.maxId();
-	  ignore_unused_variable_warning(n);
-	}
-      }
-      Graph& graph;
-    };
-
-
     class MappableGraphComponent : virtual public BaseGraphComponent {
     public: