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

[Ogi]

On Sunday, 23 August 2020 at 21:08:30 UTC, Per Nordlöw wrote:
> Why aren't more operators allowed inside `is(...)`-expressions?
>
> For instance
>
>     if (!is(CommonType!(typeof(min), typeof(max)) == void))
>
> could be written as
>
>     if (is(CommonType!(typeof(min), typeof(max)) != void))
>
> .

There is one expression where allowing “!” would be much more 
beneficial — version condition. Currently we are forced to write 
something like:
     version (OSX) {} else {
         /* ... */
     }
when it could be just:
     version (!OSX) {
         /* ... */
     }
I am aware that it was Walter’s intention to make the version 
syntax simplistic, but I don’t think that allowing “!” would do 
any harm.