Re: [Boost-users] [BGL] filtered_graph and bundled properties (was Re: [BGL] filtered_graph and null_vertex())

From: Doug Gregor (dgregor_at_[hidden])
Date: 2005-09-06 15:35:47

On Aug 15, 2005, at 3:58 PM, Tiago de Paula Peixoto wrote:
> I have one more problem with filtered_graph, but this time it has to do
> with bundled properties. If I try to compile the following program:
>
> --------------------------------------------------------------
> #include <boost/graph/adjacency_list.hpp>
> #include <boost/graph/filtered_graph.hpp>
>
> using namespace boost;
>
> struct VertexProperties
> {
>   int answer;
> };
>
>
> int main()
> {
>   typedef adjacency_list<vecS,vecS,bidirectionalS,VertexProperties> 
> graph_t;
>   typedef filtered_graph<graph_t,keep_all> f_graph_t;
>   graph_t g;
>   f_graph_t fg(g, keep_all());
>   graph_traits<f_graph_t>::vertex_descriptor v = add_vertex(g);
>   fg[v].answer = 42;
>   return 0;
> }
> --------------------------------------------------------------
> I get the following error with boost 1.33 and GCC 4.0.1:
> [snip]
> This was supposed to work right? The error is pretty clear, but I don't
> know what "local_to_global" is supposed to do, and where it should be.

Yes, it should have worked.

> I made the attached modifications to a local version of
> filtered_graph.hpp, and the code above compiles, but I don't think that
> they are right at all, since I changed the constness of the internal
> reference to the original graph.

I think we're better off using const_cast instead of changing the 
stored reference. I've fixed the problem in CVS and the fix will be 
part of the upcoming 1.33.1 release. Thanks for reporting the bug!

        Doug