Does D have "structural sharing" of immutable collections?

[David Nadlinger]

On Wednesday, 23 May 2012 at 18:39:02 UTC, Stewart Gordon wrote:
> When the tree is immutable, only lookup speed is of any real 
> relevance, so you might as well create a perfectly balanced 
> binary tree.  Or even better, an array.

An array does not facilitate sharing common subsets between 
containers, which is usually what you are aiming for when 
designing immutable containers – the idea is to get away with 
immutability performance-wise because you don't have to copy much 
on the common mutation operations.

David