Static associative array expressions

[Stefan Koch]

On Monday, 20 September 2021 at 12:38:59 UTC, Steven 
Schveighoffer wrote:
> On 9/19/21 9:38 AM, Stefan Koch wrote:
>> On Sunday, 19 September 2021 at 11:55:04 UTC, Steven 
>> Schveighoffer wrote:
>>> On 9/19/21 1:43 AM, Stefan Koch wrote:
>>>
>>>> What do you guys think?
>>>
>>> I think an easier fix is just to change the call that does 
>>> the AA literals to something that can be CTFEd. Right now 
>>> it's an extern(C) hook that is opaque and takes void[] and 
>>> TypeInfos.
>>>
>>> Something like:
>>>
>>> ```d
>>> V[K] __aALiteral(V, K)(K[] keys, V[] values);
>>> ```
>>>
>>> Then just lower the call to that, and if that is CTFEable, it 
>>> works.
>>>
>> 
>> That puts actually more pressure on CTFE to be able to adapt 
>> to different layouts.
>
> CTFE doesn't have to use runtime AAs internally, only when 
> moving to code generation would it have to call this function.
>
>> Also it introduces yet more templates, I cannot cache 
>> templates as effectively as I can runtime which I only have to 
>> generate once.
>
> Only one template per AA type.
>
> -Steve

But that would be an interpreted/or some day JITed function call 
that has to do the hashing of the values and place them into the 
right buckets.
Which would be a different function per instance.

Whereas currently the only thing that has to be interpreted is 
the toHash function.
and it only has to be called once per element.