Ruby 1.9: how can I properly upcase & downcase multibyte strings?

Question

So matz made the decision to keep upcase and downcase limited to /[A-Z]/i in ruby 1.9.1.

ActiveSupport::Multibyte

Answer 1

Case conversion is locale dependent and doesn't always round-trip, which is why Ruby 1.9 doesn't cover it (see here and here)

The unicode-util gem should address your needs.