Does D have "structural sharing" of immutable collections?

[simendsjo]

On Wed, 23 May 2012 17:05:21 +0200, Roman D. Boiko <rb at d-coding.com> wrote:

> I need some immutable collections for my D Compiler Tools project,  
> namely linked list, red-black tree, and possibly some others.
>  So I'm going to create them for my use, and later generalize. I've  
> created a project on GitHub, but didn't implement anything useful yet.

http://dlang.org/phobos/std_container.html#SList
http://dlang.org/phobos/std_container.html#RedBlackTree