Here's a couple of functions (based on Brian Bondy's example) that use WideCharToMultiByte and MultiByteToWideChar to convert between std::wstring and std::string using utf8 to not lose any data.
// Convert a wide Unicode string to an UTF8 string std::string utf8_encode(const std::wstring &wstr) { int size_needed = WideCharToMultiByte(CP_UTF8, 0, &wstr[0], (int)wstr.size(), NULL, 0, NULL, NULL); std::string strTo( size_needed, 0 ); WideCharToMultiByte (CP_UTF8, 0, &wstr[0], (int)wstr.size(), &strTo[0], size_needed, NULL, NULL); return strTo; } // Convert an UTF8 string to a wide Unicode String std::wstring utf8_decode(const std::string &str) { int size_needed = MultiByteToWideChar(CP_UTF8, 0, &str[0], (int)str.size(), NULL, 0); std::wstring wstrTo( size_needed, 0 ); MultiByteToWideChar (CP_UTF8, 0, &str[0], (int)str.size(), &wstrTo[0], size_needed); return wstrTo; }