What would you think of an iterator based approach with the following interface: // Bideirectional iterator for UTF8 / UTF16 coded data // I: Raw data iterator // C: Unicode character type template <class I, typename C> class unicode_iterator; // I: Unicode character iterator template <typename I> class unicode_string; // some standard types: typedef unicode_iterator<std::string::iterator, wchar_t> utf8_iterator; typedef unicode_iterator<std::basic_string<short>::iterator, wchar_t> utf16_iterator; typedef std::wstring::iterator utf32_iterator; typedef unicode_string<utf8_iterator> > utf8_string; typedef unicode_string<utf16_iterator> > utf16_string; typedef unicode_string<utf32_iterator> > utf32_string; This would allow a lot of algorithms to work directly together whith a "slim" unicode framework.