use feature 'unicode

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

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Re: use feature 'unicode_strings' by ikegami (Patriarch) on Mar 05, 2010 at 16:03 UTC
Some Perl operators are currently buggy. If a string consists of "à", Sometimes `uc` will uppercase it, sometimes it won't. Sometimes `/\w/` will match, sometimes it won't. etc But for "a" and for "ā", `uc` will uppercase it. `/\w/` will match. etc What's special about "à"? It's in the iso-8859-1 character set and outside of the ASCII character set. That's obviously not a reason for the current misbehaviour. This can't be fixed for backwards compatibility reasons, so a pragma was added. Unicode::Semantics::up (aka utf8::upgrade) is a hack that addresses the same issue. However, it only affects one string, the effect is fleeting, and it forces the use of a less efficient storage format. The pragma fixes all broken operators, without the side effects. And it's fixed mostly automatically; all you need is `use 5.012;`.	[reply] [d/l] [select]
Re^2: use feature 'unicode_strings' by Anonymous Monk on Mar 06, 2010 at 10:43 UTC
That was a pretty good explanation. What happens if I combine `use utf8;` and `use 5.012;`?	[reply]
Re^3: use feature 'unicode_strings' by ikegami (Patriarch) on Mar 06, 2010 at 21:09 UTC
You'll tell Perl your source in UTF-8 encoded, you want a version check for 5.12, and you want 5.12's backward-incompatible changes.	[reply]
Re: use feature 'unicode_strings' by Anonymous Monk on Mar 05, 2010 at 12:46 UTC
But did you read Unicode::Semantics?	[reply]
Re^2: use feature 'unicode_strings' by Anonymous Monk on Mar 05, 2010 at 13:27 UTC
My question was specifically about the module in the topic/title.	[reply]
Re^3: use feature 'unicode_strings' by Anonymous Monk on Mar 05, 2010 at 13:33 UTC
How does the new solution to the old problem relate to the old solution? Please explain in deeper detail that which is already explained twice in very deep detail.	[reply]