On Fri, 28 Aug 2009, Ralf Goertz wrote:
Hi,
I'm new to BGL (and generic programming) so this may well not be a bug but I don't know how this could be intended. Consider the following program:
#include <string> #include <iostream> #include <boost/graph/graph_traits.hpp> #include <boost/graph/properties.hpp> #include <boost/graph/adjacency_list.hpp>
using namespace boost;
typedef property<vertex_name_t, std::string> VertexProp; //this crashes typedef adjacency_list < vecS, vecS, undirectedS,VertexProp, no_property > graph_t; //this doesn't //typedef adjacency_list < vecS, listS, undirectedS,VertexProp, no_property > graph_t; typedef graph_traits < graph_t >::vertex_descriptor vertex_descriptor; typedef property_map<graph_t, vertex_name_t>::type id_name_map_t; typedef graph_traits<graph_t>::vertex_iterator vi_t; std::pair<vi_t,vi_t> vi;
int main(){ graph_t g; vertex_descriptor vd; id_name_map_t name_map; vd=add_vertex(g); put(name_map,vd,"foo"); for (vi=vertices(g); vi.first!=vi.second;++vi.first) { std::cout<<get(name_map,*vi.first)<<std::endl; } return EXIT_SUCCESS; }
It appears that name_map is not initialized. You need to do something like: id_name_map_t name_map = get(vertex_name, g); to get the property map before you use it. -- Jeremiah Willcock