I'm a bit confused by the documentation of ExactSizeIterator. As far as I understand, the only think I need to do it to implements the functions
size_hint() when implementing
size_hint() should return
(exact_size, Some(exact_size)) with
exact_size being the exact number of elements that will be yielded.
len() function doesn't need to be implemented and will just use
size_hint().0 => Is this right, because the example implements
len() and not