[Bug libstdc++/112641] : `drop_view::begin const` has O(n) complexity

[hewillk at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112641

--- Comment #7 from 康桓瑋 <hewillk at gmail dot com> ---
(In reply to Patrick Palka from comment #6)
> Fixed for 15 / 14.3 / 13.4

But you didn't *optimize* the non-const begin, right?