Commits
Maarten A. Breddels authored and Antoine Pitrou committed 9b162ee6c6f
ARROW-9133: [C++] Add utf8_upper and utf8_lower This is the initial working version, which is *very* slow though (>100x slower than the ascii versions). It also required libutf8proc to be present. Please let me know if the general code style etc is ok. I'm using CRTP here, judging from the metaprogramming seen in the rest of the code base, I guess that's fine. Closes #7449 from maartenbreddels/ARROW-9133 Lead-authored-by: Maarten A. Breddels <maartenbreddels@gmail.com> Co-authored-by: Antoine Pitrou <antoine@python.org> Co-authored-by: Uwe L. Korn <uwe.korn@quantco.com> Signed-off-by: Antoine Pitrou <antoine@python.org>