[common.iter.types]

The nested typedef-names of the specialization of iterator_traits for common_iterator<I, S> are defined as follows.

(1.1)
iterator_concept denotes forward_iterator_tag if I models forward_iterator; otherwise it denotes input_iterator_tag.
(1.2)
iterator_category denotes forward_iterator_tag if iterator_traits<I>::iterator_category models derived_from<forward_iterator_tag>; otherwise it denotes input_iterator_tag.
(1.3)
If the expression a.operator->() is well-formed, where a is an lvalue of type const common_iterator<I, S>, then pointer denotes the type of that expression.

Otherwise, pointer denotes void.

23 Iterators library [iterators]