[Bug libstdc++/108487] [10/11/12/13 Regression] ~20-30x slowdown in populating std::vector from std::ranges::iota_view

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108487

--- Comment #9 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I think we just want to dispatch on iterator concept not iterator category.