...classes are reference types:

class Node
{
    Node[] nodes; // This is valid
}

Structs are value types...

...a hierarchy of transforms, shapes and interactive nodes. A retained mode version of Display Postscript...

...to read XML files and replace the nodes I care about (shapes and transforms) with...

...implementation in Tango uses structs for the nodes so you cannot subclass that.

-- 
/Jacob Carlborg

...using one of those and replace the nodes I am interested with subclasses after the...

...all nodes.

* I'd like a way to iterate seeing only edges, not nodes.

* I...

...most generic one.

A variant, where the nodes store the flag internally is more efficient...

...if the dtor recursively frees all child nodes, so it's not that much better...

...after its items based on expiration of nodes. I'd like to use the new...

...using simpler, "dumber" file structures for storing nodes, with an in-memory Bloom filter to...