test

        auto* p = const_cast<char*>(reinterpret_cast<const char*>(data));

        setg(p, p, p + size);

    }

protected:

    pos_type seekoff(off_type off, std::ios_base::seekdir dir,

                     std::ios_base::openmode which = std::ios_base::in) override {

        if (which & std::ios_base::in) {

            char* p = gptr();

            if (dir == std::ios_base::beg) p = eback() + off;

            else if (dir == std::ios_base::cur) p += off;

            else if (dir == std::ios_base::end) p = egptr() + off;

            if (p < eback() || p > egptr()) return pos_type(off_type(-1));

            setg(eback(), p, egptr());

            return pos_type(p - eback());

        }

        return pos_type(off_type(-1));

    }

    pos_type seekpos(pos_type pos,

                     std::ios_base::openmode which = std::ios_base::in) override {

        return seekoff(off_type(pos), std::ios_base::beg, which);

    }

};

// ---- BinDb ----