On Apr 6, 2005, at 12:31 AM, Elvanör wrote:


<excerpt>Hello.


I have just been looking recently at the subgraph feature of the BGL.
If I understand correctly, in order to use it you *must* first create
a root subgraph; you can't use an existing Graph as the root and call
create_subgraph on that adjacency_list, for example.


It also seems like when you create a subgraph, it is somehow stored on
the root subgraph, since
<fontfamily><param>Courier</param><x-tad-bigger>create_subgraph() has
a return type of subgraph<<Graph>&.


</x-tad-bigger></fontfamily>As it returns a reference, I assume that
the actual object is somehow stored on the root. But I need to create
and delete lots of subgraphs on a given root graph. Creating the
subgraph is no problem; however how can I deleted them ??? I could
just leave them, of course, but that's an obvious waste of resources...

</excerpt>

The subgraph is stored on the root, so that when edges are
added/removed anywhere in the graph the changes can ripple throughout
the graph structure. However, there's no support for deleting
subgraphs.


<excerpt>Is there an answer to my question? If possible, I'd also like
to learn a little bit more about the subgraph implementation (all I
can suppose from the documentation is that it is stored in some kind
of tree data-strucutre).

</excerpt>

The only good answers are in the implementation itself :) 


	Doug