Does D have "structural sharing" of immutable collections?

[simendsjo]

On Wed, 23 May 2012 20:18:54 +0200, simendsjo <simendsjo at gmail.com> wrote:

> 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

And http://dsource.org/projects/dcollections