Hi there! May be I'm asking something unbeleivably stupid, but anyway here is my problem. I need to get the names of all vertices in the graph (It is GraphvizDigraph), so ---------------------------------------------------- using namespace boost; property_map< GraphvizDigraph, vertex_name_t>::type& vn = get(vertex_name, g); graph_traits<GraphvizDigraph>::vertex_iterator i; for(i = vertices(g).first; i != vertices(g).second; ++i ) { std::cout<< vn[*i]<<endl; } ---------------------------------------------------- And here is the error I got: ---------------------------------------------------- c:\Documents and Settings\MAKC\My Documents\Visual Studio Projects\Graph\MyGraph.cpp(61) : error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'boost::vec_adj_list_any_vertex_pa::bind_<Tag,Graph,Property>::value _type' (or there is no acceptable conversion) with [ Tag=boost::vertex_name_t, Graph=boost::detail::subgraph_any_pmap::bind_<boost::vertex_name_t,boost: :GraphvizDigraph,boost::detail::vertex_property_map<boost::GraphvizDigrap h,boost::vertex_name_t>::Property>::Graph, Property=boost::detail::vertex_property_map<boost::detail::subgraph_any_p map::bind_<boost::vertex_name_t,boost::GraphvizDigraph,boost::detail::ver tex_property_map<boost::GraphvizDigraph,boost::vertex_name_t>::Property>: :Graph,boost::vertex_name_t>::Property ] ----------------------------------------------------- Since this code is almost "CopyPasted" from the library example, my beleif is that it should work. At what point I have to change my worldview? :) Thanks in advance. ------------------------------------- |your sincerely, Maxx, | | mailto:maxxua@pisem.net | -------------------------------------