Re: [graph] [serialization] serialized descriptors

> 1) I have a list of descriptors in my program. This list is a  
> selection
> of vertices. If I want to serialize my program's states, I need to
> serialize the graph as well as this selection. This means I have to
> serialize references to vertices. Now AFAIK I cannot simply serialize
> descriptors, because they essentially are pointers. I need a  
> persistent
> ID. Is there existing functionality for this? If not, I have to either
> use one of the vertex properties as ID, or autogenerate IDs (for
> example, by using casting the descriptors to an intptr_t and using  
> this
> value as ID) and upon deserialization use these for mapping the right
> descriptors back into the list.

It depends on the serialization method. Are you using the Boost  
Serialization library or one of the Boost.Graph I/O functions like  
write_graphviz()?

It's been a while since I looked closely at the graph code, so take  
this with a grain of salt. Some versions of the adjacency list  
actually have implicit ids. If you declare the adjacency list with  
vector storage for vertices, then you can simply create an id  
property map over the vertices. The reason for this is that vecS  
causes the vertex descriptor to be the index into the vector, rather  
than a pointer. For any other vertex storage option, you're on your own.

>

You should probably also steer clear of the older properties  
(boost::property<>) for graphs. I would recommend defining vertex and  
edge structures that contain all the features you need for your graph  
application and then attaching property maps to them. You may end up  
having to assign your own unique id's (which could actually be  
strings) , but at least you'll know how it's going to work.

Andrew Sutton
asutton <at> cs.kent.edu

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