Generating a tree structure

[Ricky C via Digitalmars-d-learn]

I'm trying to make a tree data structure in part of my first 
non-trivial D-based program.  Turns out that DMD likes to re-use 
PODs - sounds good, but that trapped me, and I'm not sure how to 
clear myself out of the problem nicely.

My simplified, but not oversimplified, example is 
http://dpaste.dzfl.pl/67b022ca029e

You'll note in the output of the program several duplicated 
values for "self" and the parent value goes to places other than 
the parent.  This is all wrong, and shows my ignorance, but is as 
far as I've been able to work it.

In my operational code I bypassed the problem by storing every 
leaf and branch in an array and changing the self, parent, and 
children properties to be indices into said array.  But this 
feels hackish: I'd rather have the tree itself hold everything it 
needs.

Note: I'm not stuck with a struct. I could class the thing, but I 
figured that a struct holds what I need simply...

Thoughts, solutions?