I have the following example that I am using as a test. It is to figure why my method of creating a directed graph fails to meet the boost requirement of a directed graph when using topological_sort. I cannot figure out why my fuller code compiles fine and this example does not. I am trying to be explicit and not use 'using namespace boost' for example. I want to declare its found in namespace x::y::z for example. Stephen ------------ #include <boost/graph/adjacency_list.hpp> #include <boost/shared_ptr.hpp> #include <boost/cstdint.hpp> #include <boost/format.hpp> #include <boost/graph/topological_sort.hpp> #include <iostream> #include <map> class Component; class Graph_Base { public: typedef boost::property< boost::vertex_index_t, boost::uint32_t, boost::property< boost::vertex_name_t, boost::shared_ptr<Component> > > VertexProperty_t; typedef boost::adjacency_list< boost::setS, // OutEdgeList boost::setS, // VertexList boost::directedS, // Directed VertexProperty_t > // VertexProperties Graph_t; }; class Component { public: typedef boost::shared_ptr<Component> ptr_t; Component ( boost::uint32_t id ) : m_id ( id ) {} ~Component () { m_source_list.clear(); } // Now part of Component_Data void set_Data_Source ( uint32_t id ) { if ( ! m_source_list.insert ( std::make_pair ( id, false ) ).second ) { std::cerr << "WARNING: Attempted to add a duplicate component id."; std::cerr << std::endl; std::cerr << "Ignoring component id." << std::endl; } } std::map<boost::uint32_t, bool>::const_iterator get_Source_List_Begin() const { return m_source_list.begin(); } std::map<boost::uint32_t, bool>::const_iterator get_Source_List_End() const { return m_source_list.end(); } boost::uint32_t get_ID (void) const { return m_id; } private: boost::uint32_t m_id; std::map<boost::uint32_t, bool> m_source_list; }; class Component_Graph { public: typedef boost::graph_traits<Graph_Base::Graph_t>::vertex_descriptor Vertex_t; typedef boost::graph_traits<Graph_Base::Graph_t>::edge_descriptor Edge_t; typedef std::map<uint32_t, Vertex_t> IdVertexMap_t; Component_Graph () {} void add_Component ( Component::ptr_t obj_ptr ) { bool no_duplicate; IdVertexMap_t::iterator pos; Vertex_t node; if ( obj_ptr.get() == 0 ) { std::cerr << boost::format("Exception throw in %s at line %d") % __FILE__ % __LINE__ << std::endl; return; } boost::tie (pos, no_duplicate) = m_index.insert (std::make_pair(obj_ptr->get_ID(), node)); if ( no_duplicate ) { // Insertion was successful // Make a new vertex and return handle to 'node' node = add_vertex(m_graph); // Get list of Components boost::property_map<Graph_Base::Graph_t, boost::vertex_name_t>::type clist = boost::get(vertex_name, m_graph); // Assign component to vertex position clist[node] = obj_ptr; // Add vertex handle to map position pos->second = node; // Get list of indexes boost::property_map<Graph_Base::Graph_t, boost::vertex_index_t>::type ilist = get(vertex_index, m_graph); ilist[node] = obj_ptr->get_ID(); for ( std::map<boost::uint32_t,bool>::const_iterator cpos = obj_ptr->get_Source_List_Begin(); cpos != obj_ptr->get_Source_List_End(); ++cpos ) { this->add_Child ( (*cpos).first, obj_ptr ); } } else { std::cerr << "ERROR: Duplicate source found. Skipping Component" << std::endl; return; } } void add_Child ( uint32_t parent_id, Component::ptr_t obj_ptr ) { IdVertexMap_t::iterator pos; IdVertexMap_t::iterator cpos; if ( obj_ptr.get() == 0 ) { std::cerr << boost::format("Exception throw in %s at line %d") % __FILE__ % __LINE__ << std::endl; return; } pos = m_index.find (parent_id); cpos = m_index.find ( obj_ptr->get_ID() ); if (pos == m_index.end()) { std::cerr << "ERROR: Cannot find parent. Skipping adding component #" << obj_ptr->get_ID() << std::endl; return; } // Add edge from parent to child Edge_t link; if (! (add_edge ( pos->second, cpos->second, m_graph).second)) { std::cerr << "ERROR: Duplicate edge exists from " << parent_id << " to " << obj_ptr->get_ID() << std::endl; return; } } Graph_Base::Graph_t const& get_Graph () const { return m_graph; } private: Graph_Base::Graph_t m_graph; IdVertexMap_t m_index; }; int main (int, char**) { // CREATE Component_Graph Component_Graph m_graph; // Create Components Component::ptr_t node_one ( new Component ( 1 ) ); Component::ptr_t node_twenty ( new Component ( 20 ) ); node_twenty->set_Data_Source ( 1 ); Component::ptr_t node_thirty ( new Component ( 30 ) ); node_thirty->set_Data_Source ( 1 ); Component::ptr_t node_forty ( new Component ( 40 ) ); node_forty->set_Data_Source ( 1 ); Component::ptr_t node_five ( new Component ( 5 ) ); node_five->set_Data_Source ( 1 ); node_five->set_Data_Source ( 20 ); node_five->set_Data_Source ( 30 ); node_five->set_Data_Source ( 40 ); // Add Components to Graph m_graph.add_Component ( node_one ); m_graph.add_Component ( node_twenty ); m_graph.add_Component ( node_thirty ); m_graph.add_Component ( node_forty ); m_graph.add_Component ( node_five ); // Call topological_sort on graph typedef std::vector<Component_Graph::Vertex_t> m_container; m_container comp_list; boost::topological_sort ( m_graph.get_Graph(), std::back_inserter ( comp_list ) ); return 0; }