Re: [Boost-users] Storing vertex descriptors when removing a vertex

Subject: Re: [Boost-users] Storing vertex descriptors when removing a vertex
From: Jeremiah Willcock (jewillco_at_[hidden])
Date: 2011-07-07 11:11:09

On Thu, 7 Jul 2011, Orianne Siret wrote:

> Hi all,
> I am using the boost graph library for my project and encountered a small 
> problem I don't know how to solve. I had to keep in an extern storage some of 
> the vertex_descriptor in order to have access to their adjacent vertices and 
> their properties.
> But as it is written in the boost documentation, when I remove a vertex, the 
> vertex_descriptors change and I am not able to keep the right ones in my 
> storage. Is there something else apart from vertex_descriptor that won't 
> change but from which I could also access adjacent vertices and properties ?
> Thank you in advance for your help.

If you use listS as your vertex container type, vertex descriptors will be 
stable across deletions.  They will not be stable across saving and 
reloading the graph, though, since the descriptors become pointers when 
you use listS.  If you need more stability than that, have a vertex 
property that you keep manually, and an external table mapping from those 
to vertex descriptors; you would probably need to update that table on 
vertex deletions.  If you are not doing too many deletions, you could also 
use a filtered_graph to hide the vertices you don't want without deleting 
them; that would keep even vecS vertex descriptors stable.

-- Jeremiah Willcock