Teodor Sigaev <teodor@sigaev.ru> writes:
>> The regex code is working with pg_wchar strings, which aren't
>> necessarily the same representation that the OS' wide-char functions
>> expect. If we could guarantee compatibility then the above plan
>> would make sense ...
> it seems to me, that is possible for UTF8 encoding.
Why? The one thing that a wchar certainly is not is UTF8.
It might be that the <wctype.h> functions are expecting UTF16 or UTF32,
but we don't know which, and really we can hardly even be sure they're
expecting Unicode at all.
regards, tom lane