OrderedHash

[Vasily Chekalkin]

Will Coleda wrote:
> Before bacek spends a lot of energy trying to make sure that he
> doesn't break OrderedHash while trying to clean up hashes in general,
> let me ask:
> 
> Do we even want OrderedHash in core?

Thanks for question. Answer is "we need some kind of OrderedHash". But 
afaiu it's "filling only" Hash-like structure. Useful for ManagedStruct 
and Namespaces to preserve order of "keys". OTOH "keys" from this 
structure are never deleted and values are never updated.

> With 1.4 due out next month, now would be an excellent time to discuss
> removing OH from our core set of PMCs.

I'm voting to have some very small and simple PMC which isn't called 
"Hash" with "fill only" semantic. Purely for internal usage with 
disclaimer in documentation "Here will be dragons. Not for external use" 
(or something like this).

-- 
Bacek