Re: [Boost-users] [BGL] Finding the descriptor for a given vertex

Subject: Re: [Boost-users] [BGL] Finding the descriptor for a given vertex
From: Jeremiah Willcock (jewillco_at_[hidden])
Date: 2012-01-05 08:42:54

On Thu, 5 Jan 2012, Jens Müller wrote:

> Am 30.12.2011 11:27, schrieb Anders Wallin:
>> As a comment to this: when I write algorithms that do a lot of
>> modifications to a graph, a common reason for a segfault is accessing
>> the
>> bundled property (either vertex or edge) of a BGL-graph with an
>> illegal vertex/edge-descriptor. It would be useful if in debug-mode,
>> or perhaps
>> a special "safe"-mode BGL would guard against this segfault and
>> produce an assert() on  g[illegal_descriptor]
>
> I wonder whether a special graph type might be sufficient/desired here?
>
> E.g., one might want to never re-use descriptors of deleted vertices/edges 
> even by mistake.

Yes, a special graph type is probably what would be needed; that would 
also allow vertices and edges to be deleted by just hiding them, avoiding 
invalidation of other descriptors (which makes working with graphs that 
are mutated very difficult in BGL now).

-- Jeremiah Willcock