Hello, I have created a labeled graph: *typedef boost::adjacency_list UnGraph;* My labels are uint64_t, I want to have my own ids on the graph. If I add a node: m_g.add_vertex(nodeId, Item(nodeId)); Everything is fine, but there is a bug with find_labeled_vertex. I want to check if a label is in my graph: *auto BUnGraph::exists( nid source ) const -> bool* *{* * if( m_g.vertex(source) == UnGraph::null_vertex() )* * return false;* * else* * return true;* *}* But the method vertex(source) gives me false results, and returns me a default constructed vertex_descriptor when a node is not in the graph instead of a null_vertex(). I have isolated the method. labeled_graph.hpp * /** @name Find Labeled Vertex */* * //@{* * // Tag dispatch for sequential maps (i.e., vectors).* * template * * typename graph_traits<Graph>::vertex_descriptor* * find_labeled_vertex(Container const& c, Graph const&, Label const& l,* * random_access_container_tag)* * { return l < c.size() ? c[l] : graph_traits<Graph>::null_vertex(); }* I have checked the internal map. If I add a single node in the graph, map.size() == 42. Instead of 1 ! If I add 5 nodes size() == 248. *So any label number inferior to map.size() will give false results ...* What's going on ? Thank you.