DIP60: @nogc attribute

[via Digitalmars-d]

On Tuesday, 22 April 2014 at 16:58:23 UTC, Kapps wrote:
> iOS now on 64-bit processors doesn't necessarily use a hashtable
> for refcounting. Basically, only 33 bits of the 64-bit pointer
> are used to actually refer to an address, then 19 of the
> remaining bits are used to store an inline reference count.

I am sure you are right, but how does that work? Do you have a 
link?