The iterator does not specialize `size_hint`, `fold`, `count`, `nth` and the like, and does not implement `ExactSizeIterator`, etc. These could give a huge performance boost to the iterator in some cases.
The iterator does not specialize
size_hint,fold,count,nthand the like, and does not implementExactSizeIterator, etc.These could give a huge performance boost to the iterator in some cases.