Hi
I tried to compile this example:

typedef boost::adjacency_list <boost::listS,boost::listS,boost::undirectedS,vertex_descriptor > Graph;
   typedef boost::graph_traits<Graph>::vertex_descriptor v_des;
   typedef boost::graph_traits<Graph>::vertex_iterator v_iter;
   typedef boost::graph_traits<Graph>::edge_descriptor e_des;
   typedef boost::graph_traits<Graph>::edge_iterator e_iter;
   Graph newg;

......// insert data in newg

v_iter vit, ve;
int index = 0;
for(boost::tie(vit,ve)=boost::vertices(newg); vit!=ve; ++vit ){
    v_des vd = *vit;
    vd->id()= index++;
    }

but the reply is: "void*" is not a pointer-to-object type at the last line.
What kind of error it is?? How can I solve this problem??
Thanks
Best regards
-Bombielfil-