Using iterators with callback APIs

[jgarvin]

@2e71828

'_ in FnMut(...) is shorthand for a higher-ranked trait bound

Are you saying this is is some sort of convention, or does '_ actually have special different meaning inside FnMut than it normally does? I thought '_ was always just a standin for a regular lifetime.

@2e71828

In this case, it's because Change.location points to a buffer that for_each_to_obtain_tree() is altering between calls to the closure.

So tying into our other discussion this could in theory be changed to an API based on LendingIterator? But also curious if there's anything I can do without changing the original crate, to be able to use Iterator methods in this situation?