On Saturday, 14 May 2022 at 09:45:33 UTC, H. S. Teoh wrote:
> TBH, for cases like these, I'd just use a pointer and check for null
>
> [...]
>
> No need to fear pointers, they're in the language for a reason.

Quite fair, of course.  One doesn't _need_ mutable auto ref to achieve the use cases above ... but one could conceivably use it if one was so inclined.