+ const GraphType &Graph;
+
+ inline Inverse(const GraphType &G) : Graph(G) {}
+};
+
+// Provide a partial specialization of GraphTraits so that the inverse of an
+// inverse falls back to the original graph.
+template<class T>
+struct GraphTraits<Inverse<Inverse<T> > > {
+ typedef typename GraphTraits<T>::NodeType NodeType;
+ typedef typename GraphTraits<T>::ChildIteratorType ChildIteratorType;
+
+ static NodeType *getEntryNode(Inverse<Inverse<T> > *G) {
+ return GraphTraits<T>::getEntryNode(G->Graph.Graph);
+ }
+
+ static ChildIteratorType child_begin(NodeType* N) {
+ return GraphTraits<T>::child_begin(N);
+ }