--- James Jackson wrote:
Hi,
Hello!
I am trying to use the BGL to model a simple directed graph with internal edge properties. Following the example given in the documentation[1], I have done the following (with question-irrelevant padding removed):
------------------------------- #include <boost/graph/adjacency_list.hpp> #include <boost/property_map.hpp>
typedef boost::property<boost::edge_weight_t, double> EdgeProperties; typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::no_property, EdgeProperties> NetworkGraph; typedef std::pair<int, int> Edge;
NetworkGraph g(5); boost::add_edge(0, 1, g); boost::add_edge(0, 2, g); boost::add_edge(1, 3, g); boost::add_edge(2, 3, g); boost::add_edge(3, 4, g);
boost::property_map<NetworkGraph, boost::edge_weight_t>::type weights = boost::get(boost::edge_weight_t(), g); weights[0] = 1.0; weights[1] = 1.0; weights[2] = 1.0; weights[3] = 1.0; weights[4] = 1.0; -------------------------------
Which all looks fairly kosher.
Sorry, it isn't. Edge maps require edge_descriptors for keys. First, change your Edge type definition to this: typedef NetworkGraph::edge_descriptor Edge; Then, for adding edges, do the following: Edge e; bool b; boost::tie(e, b) = boost::add_edge(0, 1, g); if (b) { weights[e] = 1.0; } // etc. HTH, Cromwell D. Enage ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs