Proposed resolution:

This wording is relative to N4981.

1. Modify [range.utility.helpers] as indicated:

   […]
   
   template<class I>
     concept has-arrow =                                       // exposition only
       input_iterator<I> && (is_pointer_v<I> || requires(const I i) { i.operator->(); });
   
   […]
   

[ Wrocław 2024-11-23; Status changed: Voting → WP. ]

[ St. Louis 2024-06-24; move to Ready ]

The helper concept has-arrow in [range.utility.helpers] does not require that I::operator->() be const-qualified, which is inconsistent with the constraints on reverse_iterator and common_iterator's operator->() as the latter two both require the underlying iterator has const operator->() member.

We should enhance the semantics of has-arrow so that implicit expression variations ([concepts.equality]) prohibit silly games.