Associative Arrays max length? 32bit/64bit

[FG via Digitalmars-d]

On 2014-05-17 21:35, bearophile wrote:
> FG:
>
>> and don't forget the extra memory needed to store the tree for fast key look-up in the hash array.
>
> I think D now uses a linked list for the collision chains (so opCmp is useless, despite it's still required for the hashing protocol).

Indeed, I just read https://github.com/D-Programming-Language/dmd/blob/master/src/backend/aa.c
Key hash is divided modulo the number of buckets and each bucket points to an ordered double-linked list. That list is walked left or right depending on what value Typeinfo::compare returns for two keys. Hmm... isn't opCmp used by that function? Why useless?