Advanced node structure design

[ugly.creep]

I have the idea to build a library of classes to represent a node
structure where:

- nodes can store relations with other nodes that are not necessarily
parent-child (but can be); the different relations of a node can be
'queried'. A relation type might be related to a problem domain which
is not relevant at this level.
- nodes are part of a nodestructure (I could say 'tree', but it's not
limited to parent-child only)
- nodestructures can be compared
- nodestructures can be large, and e.g. one large nodestructure
original will reside in memory, and you can apply 'delta'
nodestructures (i.e. changes to the large original nodestructure)
- there's a generic interface that provides access to a nodestructure.
'Delta' nodestructures are treated in a transparent way; accessors do
not directly see a difference.

I was just curious if there are similar implementations that might be
of inspiration?

I'm sure I would still have to provide my own implementation because
the above leaves out a lot of additional functionality (such as node
types, properties, etc.).

I want to note that this will be C++ and will also rely on the stl and
boost libraries.

Feedback will be appreciated, thanks.

Regards,

E.

[ectoplasm]

You're asking a very specific design solution. I'm guessing you have
unmentioned criteria / requirements. How about listing all these for
yourself, and also, *how* exactly would you like to USE such a data
structure? (even exact syntax examples, or pseudo code) Write it all
down. I'm guessing that will result in your design being 80% finished.
And THEN you might come up with questions that apply in more general C+
+ design.