https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63776
--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Tom Straub from comment #2) > Hi Tim, > > Okay, a program very similar to this using the Boost REGEX library and ICU > 4.55 works just fine with this. > > According to my understanding, the "char" data type and "std::string" > classes were specifically set up in C++11 to handle UTF-8 sequences. Nothing was done to char or std::string because they can already hold UTF-8 data. The new u8 literal prefix was added to produce UTF8-encoded string literals. > The "sequence of bytes" are actually valid UNICODE characters. Right, and if your source character set wasn't UTF-8 you could still initialize the std::string correctly with e.g. std::string s = u8"Jo\u00e3o M\u00e9ro\u00e7o"; > It is acting as if it is still in POSIX or C locale, since it doesn't > recognize the accented characters as "[:alpha:]" class. Yes, I don't know how it's supposed to work in <regex> but I agree there seems to be a bug. (In reply to Tim Shen from comment #1) > I don't know much about unicode support status in the standard library. > @Jon, can you put a comment? We're missing the facilities for converting between different unicode encodings which would allow us to convert multibyte char strings to wchar_t so that we can use the ctype<wchar_t>::is(ctype_base::mask, wchar_t) function to match non-ASCII characters. Maybe a workaround for now would be to detect when we reach the first byte of a UTF-8 character, read the rest of the multibyte character into a wchar_t and use ctype<wchar_t> for that. Or just wait for the rest of the ctype and codecvt features to be implemented.
