Does D have "structural sharing" of immutable collections?

[bearophile]

Roman D. Boiko:

> The end goal is to have something as easy to work with as 
> collections of Scala or F# (I don't know Haskell), and, of 
> course, efficient.

If you plan in creating a start of purely functional collections 
library then I suggest you to also take a look at Clojure and 
various Haskell collections. Clojure is very based on persistent 
purely functional data structures, used in modern ways. And in 
the Haskell tribe there are some very smart persons that have 
worked on those things for fifteen years. So spending one extra 
week reading and looking at those two worlds may help you a lot 
later, and give you many good/better ideas.

Bye,
bearophile