Function utf8to16

external/utf8/cpp11.h:47–52

    }

    inline std::u16string utf8to16(const std::string& s)
    {
        std::u16string result;
        utf8to16(s.begin(), s.end(), std::back_inserter(result));
        return result;
    }

    inline std::string utf32to8(const std::u32string& s)
    {