is(x = module) vs. __traits(isModule, x)

[Stefan Koch]

On Saturday, 10 October 2020 at 00:16:32 UTC, Walter Bright wrote:
> On 10/8/2020 7:19 AM, Steven Schveighoffer wrote:
>> I think the AliasSeq pattern still runs through the template 
>> machinery, which is not a good thing. But perhaps this can be 
>> addressed orthogonally.
>
> Nah, it short-circuits that machinery. Recognizing the AliasSeq 
> pattern and doing it directly was a huge win.
>
> We can do the same as necessary for __traits if it comes to 
> that.

It was not a huge win.

In certain circumstances it won.
On others it lost.

Bypassing the cache is not good.