How do I get STL std::string to work with unicode on windows?

Question

At my company we have a cross platform(Linux & Windows) library that contains our own extension of the STL std::string, this class provides all sort of functionality on top

Answer 1

No, there is no way to make Windows treat "narrow" strings as UTF-8.

Here is what works best for me in this situation (cross-platform application that has Windows and Linux builds).

• Use std::string in cross-platform portion of the code. Assume that it always contains UTF-8 strings.
• In Windows portion of the code, use "wide" versions of Windows API explicitly, i.e. write e.g. CreateFileW instead of CreateFile. This allows to avoid dependency on build system configuration.
• In the platfrom abstraction layer, convert between UTF-8 and UTF-16 where needed (MultiByteToWideChar/WideCharToMultiByte).

Other approaches that I tried but don't like much:

• typedef std::basic_string tstring; then use tstring in the business code. Wrappers/overloads can be made to streamline conversion between std::string and std::tstring, but it still adds a lot of pain.
• Use std::wstring everywhere. Does not help much since wchar_t is 16 bit on Windows, so you either have to restrict yourself to BMP or go to a lot of complications to make the code dealing with Unicode cross-platform. In the latter case, all benefits over UTF-8 evaporate.
• Use ATL/WTL/MFC CString in the platfrom-specific portion; use std::string in cross-platfrom portion. This is actually a variant of what I recommend above. CString is in many aspects superior to std::string (in my opinion). But it introduces an additional dependency and thus not always acceptable or convenient.