Re: [Boost-users] [BGL] filtered graph missing vertex function

From: Stephan Diederich (S.Diederich_at_[hidden])
Date: 2006-09-05 14:59:36

Hi Moritz,

2006/9/5, moritz Hilger <moritz.hilger_at_[hidden]>:
- Zitierten Text anzeigen -
> is there a particular reason that the filtered graph is missing a
> vertex_descriptor vertex(vertices_size_type, const& filtered_graph)
> function? of course this would return exactly the same as the one of the
> underlying graph, nevertheless it would be handy for code treating filtered
> graphs the same way as normal ones.

I think the problem here is the return value of the function. If you
have a VertexPredicate set, it would be possible that the vertex you
specify through the index doesn't exist in the filtered graph.
Maybe a null_vertex() could be returned in that case (But, IIRC, that
null_vertex() doesn't exist in every graph).

Cheers,
Stephan