[boost] [graph] named_graph

Hello, Looking for a way to add index of vertices by some id to adjacency_list graph I notices it derives from maybe_named_graph that should support this. However I didn't find any example nor really usable description of how to use it (I'd need to define boost::graph::internal_vertex_name, but I don't know what the typedef is supposed to be). Is there any code that uses this, anywhere? -- - Jan Hudec