hi, i have stored some bundled properties for an edge. * class EdgeProperties { public: int targetI;// Terminal No. interms of target node int sourceI;// Terminal No. interms of source node EdgeProperties(int s,int t):sourceI(s-1),targetI(t-1) { } };* my Graph is : *typedef boost::adjacency_list<boost::listS,boost::listS,boost::bidirectionalS, EdgeProperties *> Graph; Graph g; * Now iam iterating through in_edges of some vertex v; *graphtraits<Graph>::in_edge_iterator iedge_s,iedge_end; for(boost::tie(iedge_s,iedge_end) = boost::in_edges(v,g); iedge_s!=iedge_end; ++iedge_s){ EdgeProperties *ep = g[*iedge_s]; // <==== **Line 10** cout << ep->sourceI << endl; // <==== **This is giving segmentation fault;** } * I checked the *ep* pointer. it is coming out as null in line 10; is there any problem while using *in_edge_descriptor* as *edge_descriptor**( for g[edge_descriptor]* ) in *Line 10* ?? * *please help. - Phani. * *