Windows experience is atrocious

[Kagamin]

On Monday, 31 July 2023 at 14:43:20 UTC, Steven Schveighoffer 
wrote:
> `in` means `in ref` semantically (you assume it's passed by 
> reference). So there's no benefit to specifying that physical 
> pass-by-ref is required.

With `-preview=in` `in` means abstraction agnostic about ref, 
when you observe ref that's a leak of abstraction. The benefit of 
specifying ref is to make semantics definite about ref.