More operators inside `is(...)` expressions

[Alexandru Ermicioi]

On Wednesday, 26 August 2020 at 11:44:22 UTC, Steven 
Schveighoffer wrote:
> No worries! My point actually was that I don't think such 
> "chains" are valid, even without the !=. Do you have a valid 
> case that works today (without !=)?
>
> -Steve

Well, you're right, it doesn't work even with ==, right now. I 
was pretty sure it should've worked. Seems that ==, is only 
allowed as first element in a 'is' chain, which is 
counter-intuitive.

- Alex.