diff -r 4ea2147274db -r d4acebef7276 src/lemon/bits/iterable_graph_extender.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lemon/bits/iterable_graph_extender.h	Tue Apr 05 12:30:46 2005 +0000
@@ -0,0 +1,250 @@
+// -*- c++ -*-
+#ifndef LEMON_ITERABLE_GRAPH_EXTENDER_H
+#define LEMON_ITERABLE_GRAPH_EXTENDER_H
+
+#include <lemon/invalid.h>
+
+namespace lemon {
+  
+  template <typename _Base>
+  class IterableGraphExtender : public _Base {
+  public:
+
+    typedef _Base Parent;
+    typedef IterableGraphExtender<_Base> Graph;
+
+    typedef typename Parent::Node Node;
+    typedef typename Parent::Edge Edge;
+
+
+    class NodeIt : public Node { 
+      const Graph* graph;
+    public:
+
+      NodeIt() {}
+
+      NodeIt(Invalid i) : Node(i) { }
+
+      explicit NodeIt(const Graph& _graph) : graph(&_graph) {
+	_graph.first(*static_cast<Node*>(this));
+      }
+
+      NodeIt(const Graph& _graph, const Node& node) 
+	: Node(node), graph(&_graph) {}
+
+      NodeIt& operator++() { 
+	graph->next(*this);
+	return *this; 
+      }
+
+    };
+
+
+    class EdgeIt : public Edge { 
+      const Graph* graph;
+    public:
+
+      EdgeIt() { }
+
+      EdgeIt(Invalid i) : Edge(i) { }
+
+      explicit EdgeIt(const Graph& _graph) : graph(&_graph) {
+	_graph.first(*static_cast<Edge*>(this));
+      }
+
+      EdgeIt(const Graph& _graph, const Edge& e) : 
+	Edge(e), graph(&_graph) { }
+
+      EdgeIt& operator++() { 
+	graph->next(*this);
+	return *this; 
+      }
+
+    };
+
+
+    class OutEdgeIt : public Edge { 
+      const Graph* graph;
+    public:
+
+      OutEdgeIt() { }
+
+      OutEdgeIt(Invalid i) : Edge(i) { }
+
+      OutEdgeIt(const Graph& _graph, const Node& node) 
+	: graph(&_graph) {
+	_graph.firstOut(*this, node);
+      }
+
+      OutEdgeIt(const Graph& _graph, const Edge& edge) 
+	: Edge(edge), graph(&_graph) {}
+
+      OutEdgeIt& operator++() { 
+	graph->nextOut(*this);
+	return *this; 
+      }
+
+    };
+
+
+    class InEdgeIt : public Edge { 
+      const Graph* graph;
+    public:
+
+      InEdgeIt() { }
+
+      InEdgeIt(Invalid i) : Edge(i) { }
+
+      InEdgeIt(const Graph& _graph, const Node& node) 
+	: graph(&_graph) {
+	_graph.firstIn(*this, node);
+      }
+
+      InEdgeIt(const Graph& _graph, const Edge& edge) : 
+	Edge(edge), graph(&_graph) {}
+
+      InEdgeIt& operator++() { 
+	graph->nextIn(*this);
+	return *this; 
+      }
+
+    };
+
+    /// Base node of the iterator
+    ///
+    /// Returns the base node (ie. the source in this case) of the iterator
+    ///
+    /// \todo Document in the concept!
+    Node baseNode(const OutEdgeIt &e) const {
+      return source(e);
+    }
+    /// Running node of the iterator
+    ///
+    /// Returns the running node (ie. the target in this case) of the
+    /// iterator
+    ///
+    /// \todo Document in the concept!
+    Node runningNode(const OutEdgeIt &e) const {
+      return target(e);
+    }
+
+    /// Base node of the iterator
+    ///
+    /// Returns the base node (ie. the target in this case) of the iterator
+    ///
+    /// \todo Document in the concept!
+    Node baseNode(const InEdgeIt &e) const {
+      return target(e);
+    }
+    /// Running node of the iterator
+    ///
+    /// Returns the running node (ie. the source in this case) of the
+    /// iterator
+    ///
+    /// \todo Document in the concept!
+    Node runningNode(const InEdgeIt &e) const {
+      return source(e);
+    }
+
+    using Parent::first;
+
+  private:
+
+    // /// \todo When (and if) we change the iterators concept to use operator*,
+    // /// then the following shadowed methods will become superfluous.
+    // /// But for now these are important safety measures.
+
+    // void first(NodeIt &) const;
+    // void first(EdgeIt &) const;
+    // void first(OutEdgeIt &) const;
+    // void first(InEdgeIt &) const;
+
+  };
+
+
+
+
+
+  
+  template <typename _Base>
+  class IterableUndirGraphExtender : public IterableGraphExtender<_Base> {
+  public:
+
+    typedef IterableGraphExtender<_Base> Parent;
+    typedef IterableUndirGraphExtender<_Base> Graph;
+    typedef typename Parent::Node Node;
+
+    typedef typename Parent::UndirEdge UndirEdge;
+
+    class UndirEdgeIt : public Parent::UndirEdge { 
+      const Graph* graph;
+    public:
+
+      UndirEdgeIt() { }
+
+      UndirEdgeIt(Invalid i) : UndirEdge(i) { }
+
+      explicit UndirEdgeIt(const Graph& _graph) : graph(&_graph) {
+	_graph.first(*static_cast<UndirEdge*>(this));
+      }
+
+      UndirEdgeIt(const Graph& _graph, const UndirEdge& e) : 
+	UndirEdge(e), graph(&_graph) { }
+
+      UndirEdgeIt& operator++() { 
+	graph->next(*this);
+	return *this; 
+      }
+
+    };
+
+    class IncEdgeIt : public Parent::UndirEdge { 
+      const Graph* graph;
+      bool forward;
+      friend class IterableUndirGraphExtender;
+      template <typename G>
+      friend class UndirGraphExtender;
+    public:
+
+      IncEdgeIt() { }
+
+      IncEdgeIt(Invalid i) : UndirEdge(i), forward(false) { }
+
+      IncEdgeIt(const Graph& _graph, const Node &n)
+	: graph(&_graph)
+      {
+	_graph._dirFirstOut(*this, n);
+      }
+
+      IncEdgeIt(const Graph& _graph, const UndirEdge &ue, const Node &n)
+	: graph(&_graph), UndirEdge(ue)
+      {
+	forward = (_graph.source(ue) == n);
+      }
+
+      IncEdgeIt& operator++() {
+	graph->_dirNextOut(*this);
+	return *this; 
+      }
+    };
+
+    using Parent::baseNode;
+    using Parent::runningNode;
+
+    /// Base node of the iterator
+    ///
+    /// Returns the base node of the iterator
+    Node baseNode(const IncEdgeIt &e) const {
+      return _dirSource(e);
+    }
+    /// Running node of the iterator
+    ///
+    /// Returns the running node of the iterator
+    Node runningNode(const IncEdgeIt &e) const {
+      return _dirTarget(e);
+    }
+
+  };
+}
+
+#endif // LEMON_GRAPH_EXTENDER_H