[foldr]

It’s just a multiple wh construction as in

    Who arrived when?

which you might answer with e.g. “John on Tuesday and Mary on Wednesday”. This one is a bit harder to parse because it’s longer, but the answers will be something like “it can access region A at time T, region B at time T’, …”

[tialaramex]

Right, in particular objects (in the general sense, not the OOP sense) have lifetimes and so the provenance of a pointer to or into that object is restricted to the lifetime.

If I make a Box<Goose> some heap is allocated and my Goose is in there, and I can get myself a pointer to that Goose, but the pointer must not be used either before I made the Box<Goose> or after it's dropped.

[aredox]

Thanks!I really couldn't recognise it was this construction here!