Vladimir Prus wrote:
Adam Badura wrote:
I looked on a few GUI C++ libraries, but none of them satisfied me. Most commonly of this reasons: 1) weak support if at all for exceptions (wxWidgets for example) 2) using own classes instead of standard (most common for string) (wxWidgets and MFC for example)
Well, given that std::basic_string's support for Unicode is lacking, I would consider using custom string class an advantage of those libraries. Hey, you can't even convert std::string to std::wstring, and you can't construct std::wstring from char*. Can you convert std::wstring to any of Unicode's normalization forms? How portable is reading of std::wstring from a file with specific 8-bit encoding?
WRT the MFC/ATL/WTL libraries, they use the Win32 API calls WideCharToMultiByte (WC2MB) and MultiByteToWideChar (MB2WC) to do the conversion using the current thread's codepage. Likewise, their CA2W/CW2A helper classes do a similar thing. The WC2MB/MB2WC API allow you to pass in a specific codepage (not just the current thread/user's). Some of these include: UTF7 = 65000 UTF8 = 65001 UTF16 (Little Endian) = 1200 UTF16 (Big Endian) = 1200 So, you could say something like: std::cout << unicode_cast< std::string >( russian_text, unicode::utf8 ); where, on windows, unicode_cast uses WC2MB/MB2WC and unicode::utf8 is the UTF8 codepage (65001). Going the other way, reading std::wstring from a file... you can detect UTF8/16/32 (LE and BE) by having a Byte Order Mark (BOM) at the start of the file (defined at www.unicode.org) -- this is what is done in Windows. Then you can say: 0xFE 0xFF -- unicode::utf16be; 0xFF 0xFE -- unicode::utf16le; 0xEF 0xBB 0xBF -- unicode::utf8; Then you could have something like: operator>>( std::basic_istream< char > * is, std::wstring & str ) { std::string s; is >> s; // read in a string in its native (raw) form str = unicode_cast< std::wstring >( s, is.unicode_format()); return is; } where *stream::unicode_format() returns the identified unicode form, or some implementation-specific default value. I am not sure about how this would work for Linux, Mac and other operating systems, though. - Reece