Re: [Boost-users] Re: write_graphviz: write out edges when vertex data is a boost::shared_ptr?

From: Meredith L. Patterson (mlp_at_[hidden])
Date: 2004-11-08 21:28:50

Stephen torri wrote:
> The problem with the edge labelling still remains. I see a problem with the
> loop in graphviz.hpp that prints out the edges:
> 
>     typename graph_traits<Graph>::edge_iterator ei, edge_end;
>     for(tie(ei, edge_end) = edges(g); ei != edge_end; ++ei) {
>       out << source(*ei, g) << Traits::delimiter() << target(*ei, g) <<
> " ";
>       epw(out, *ei); //print edge attributes
>       out << ";" << std::endl;
>     }
> 
> There is no operator<< function for graph_traits so the memory location
> of the vertex_descriptor that is returned is printed instead of the
> vertex_index_t value used to name the nodes above. 

I ran into this exact same problem a few days ago, and posted about it 
(even referring to the same code snippet you did), but received no 
response. I eventually ended up modifying the loop in graphviz.hpp, 
replacing

  out << source(*ei, g) << Traits::delimiter() << target(*ei, g)) << " ";

with

  out << get(vertex_index, source(*ei, g)) << Traits::delimiter() << 
      \
      get(vertex_index, target(*ei, g)) << " ";

Let's hear it for the BSD license.

Cheers,
Meredith L. Patterson