c++ - Does POSIX regex.h provide unicode or basically non-ascii characters?

Question

Hi i am using Standard Regex Library (regcomp, regexec..). But now on demand i should add unicode support to my codes for regular expressions.

Does Standard Regex Library provide unicode or basically non-ascii characters? I researched on the Web, and think not.

My project is resource critic therefore i don't want to use large libraries for it (ICU and Boost.Regex).

Any help would be appreciated..

Answer 1

Basically, POSIX regexes are not Unicode aware. You can try to use them on Unicode characters, but there might be problems with glyphs that have multiple encodings and other such issues that Unicode aware libraries handle for you.

From the standard, IEEE Std 1003.1-2008:

Matching shall be based on the bit pattern used for encoding the character, not on the graphic representation of the character. This means that if a character set contains two or more encodings for a graphic symbol, or if the strings searched contain text encoded in more than one codeset, no attempt is made to search for any other representation of the encoded symbol. If that is required, the user can specify equivalence classes containing all variations of the desired graphic symbol.

Maybe libpcre would work for you? It's slightly heavier than POSIX regexes, but I would think it lighter than ICU or Boost.