Good day, I’ve been trying several things to fix my problem, yet, I just get more errors when I do. So here’s my best shot: I have an adjacent_list graph define as such: typedef adjacency_list<vecS, listS, bidirectionalS, property<vertex_index_t, int, ObjectID>, Relationships> Graph; My visitor is define as class DFSTreeVisitor : public default_dfs_visitor { public: DFSTreeVisitor(ModelTreeIF::ExplorerIF& Explorer, ModelTreeIF& Tree) : m_Tree(Tree), m_Explorer(Explorer) {}; template<typename VertexType, typename GraphType> void discover_vertex(VertexType V, const GraphType& G); template<typename VertexType, typename GraphType> void finish_vertex(VertexType V, const GraphType& G); private: ModelTreeIF& m_Tree; ModelTreeIF::ExplorerIF& m_Explorer; }; When doing a depth first search using a start location: depth_first_search(*GetGraph(RootID), visitor(Visitor), get(vertex_index, *GetGraph(RootID)), m_Vertices[StartID]); I get the following errors: Error 1 error C2039: 'initialize_vertex' : is not a member of 'boost::bgl_named_params<T,Tag,Base>' …\boost\graph\depth_first_search.hpp 197 Error 2 error C2039: 'start_vertex' : is not a member of 'boost::bgl_named_params<T,Tag,Base>' …\boost\graph\depth_first_search.hpp 200 Error 3 error C2039: 'start_vertex' : is not a member of 'boost::bgl_named_params<T,Tag,Base>' …\boost\graph\depth_first_search.hpp 207 Yet, if I use the two argument version of the function: depth_first_search(*GetGraph(RootID), visitor(Visitor)); It works fine. What wrong with my visitor? Or is it an unrelated problem in my code that causes this? Thanks you very much for you help, Jean-Olivier No virus found in this outgoing message. Checked by AVG. Version: 7.5.524 / Virus Database: 269.23.9/1417 - Release Date: 5/6/2008 8:07 AM