[Boost-users] [BGL] segFault

Subject: [Boost-users] [BGL] segFault
From: John Robertson (jrobertson7711_at_[hidden])
Date: 2010-08-21 02:06:13

I'm trying to obtain an iterator of edges with a different ordering than that 
given in egdes(g).

The following compiles but segfaults at 
std::sort( VE.begin(), VE.end(), ordering< Graph, edd >() );
(runs ok if the above line is commented out)

////////////////////////////////////////////////////////////////////////////////////////////////////////////////

  typedef Traits::edge_descriptor edd;

  // Create ordering
  template < typename Graph, typename edd >
    struct ordering {
        Graph & g;
                bool operator ()(const edd & a, const edd & b) {
                        return g[a].eName < g[b].eName;
                }
    };

  template < typename Graph >
    int initialize_container( Graph & g )
  {

    typename graph_traits<Graph>::edge_iterator edge_iter, edges_end;

    // create vector of edge descriptors.
    std::vector< Traits::edge_descriptor > VE(num_edges(g)+1);

    int i = 1;  // (Sometimes I like to start at 1.)

        //insert edge descriptors into vector of edge descriptors.
        for (tie(edge_iter, edges_end) = edges(g); edge_iter != edges_end; 
++edge_iter) {
                cout << " *edge_iter = " << *edge_iter << endl;
                VE[i++] = *edge_iter;
        }

         // segfaults here
        //sort vector of edge descriptors.
        std::sort( VE.begin(), VE.end(), ordering< Graph, edd >() );

        //print sorted edge descriptors.
        for( int i = 1; i < num_edges(g)+1; ++i )
                cout << " -Edge " << i << " = " << VE[i] << endl;

  }

Thanks