is there a reason declarative style if are allowed, but not while ?

[deadalnix]

On Sunday, 28 February 2021 at 14:32:32 UTC, Timon Gehr wrote:
> I don't think there's any good reason.
>
> Related: https://issues.dlang.org/show_bug.cgi?id=16140
>
> FWIW, note that this works in C++.

Is there a way to expedite this? This seems like an obvious 
improvement.