When I run my program the output gives an id to each edge and vertex like so. <edge id="e262" source="n46" target="n43"> This must be the index. So how can I access this index? When I put the following in my code it fails to compile. error: ‘index_map’ was not declared in this scope for (tie(edge_iter, edges_end) = edges(g); edge_iter != edges_end; ++edge_iter) { get(index_map, *edge_iter, g); } Do I need "get_property(index_map) or something? My Graph declaration is as follows. typedef adjacency_list < listS, vecS, directedS >::edge_descriptor edge_t; typedef adjacency_list < listS, vecS, directedS >::vertex_descriptor vertex_t; typedef adjacency_list < listS, vecS, directedS, property< vertex_predecessor_t, vertex_t, vertex_properties >, property< edge_reverse_t, edge_t, edge_properties > > graph_t; Thanks