Re: [Boost-users] Default weight map doesn't work for weighted grid graph in A-star search

Subject: Re: [Boost-users] Default weight map doesn't work for weighted grid graph in A-star search
From: W.P. McNeill (billmcn_at_[hidden])
Date: 2010-07-01 14:33:44

I was trying to avoid inheriting from boost::grid_graph.  The only reason I
did it here was because astar_search requires its graph to
define vertex_property_type and vertex_index, and the only way I could see
to do that was with a subclass.

I'll look at defining my own graph class that has a boost::grid_graph as a
member.

I'm still going to have to define vertex_property_type for the class I write
though, right?  What should it be: vertex_descriptor?

On Thu, Jul 1, 2010 at 11:01 AM, Jeremiah Willcock <jewillco_at_[hidden]>wrote:

> On Thu, 1 Jul 2010, W.P. McNeill wrote:
>
>  Compiling with
>> https://svn.boost.org/svn/boost/trunk/boost/graph/astar_search.hpp(r63472).  Looks like the same error.  I included a little more of the error
>> spew in case it helps.
>>
>> One thing I'm confused about: what
>> should weighted_grid::vertex_property_type be?  I didn't see anything in the
>> a-star documentation about this type, but I had to add it in order to get
>> things to compile this far.  Right now I've got it set to vertex_descriptor,
>> though I get the same error if it's vertices_size_type.
>>
>
> I think that you shouldn't try to inherit from BGL graph types.  There are
> several traits classes that are used to look things up, and those do not
> respect inheritance (i.e., graph_traits<derived> has no relationship to
> graph_traits<base>).  You should use a separate external property for your
> weights or define a separate graph type (that may contain a grid_graph, but
> has its own members/specializations for all of the traits).
>
> -- Jeremiah Willcock
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