On Tuesday, 3 June 2014 at 13:30:13 UTC, Steven Schveighoffer wrote:
> There is a school of thought (to which I subscribe) that says you shouldn't allocate a separate closure for each loop iteration.
>
> Basically, a closure will only use the stack frame of the calling function, not any loop iteration.
>
> This way, you can clearly delineate what scope the closure has, and avoid unnecessary allocations.

This is already a level too deep - it closes over variables, not the stack frame. And from this point of view, the current behavior is clearly wrong, because there is a different variable in each iteration; it just happens to have the same name.