Why iterator doesn't have any reset method?

Question

Why? And what the best way to move iterator items pointer to the first position?

Answer 1

Why?

Because if you force iterator to have a reset method every iterator has to have a reset method. That gives every iterator writer extra work. Plus some iterators are really hard (or really expensive) to reset, and you wouldn't want users to call reset on them. Iterators over files or streams are good examples.

what the best way to move iterator items pointer to the first position?

Create a new iterator. It's rarely more expensive than the reset.