[Bug libstdc++/94674] std::ranges::basic_istream_view::iterator is missing std::iterator_traits entries

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94674

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Your mistake is thinking that the iterators of views are like the iterators
you're used to.

They're not.

They have different properties (e.g. they might not be copyable, they might not
have operator->, they might not define iterator_category) and
std::iterator_traits is for use with the old kind of iterators, not the new
ones.