    /*
     *  call-seq:
     *     bv.next_from(from) -> bit_num
     *
     *  Returns the next set bit in the bit-vector scanning from low order to
     *  high order and starting at +from+. The scan is inclusive so if
     *  +from+ is equal to 10 and +bv[10]+ is set it will
     *  return the number 10. If the bit-vector has been negated than you should
     *  use the +#next_unset_from+ method.
     */
    VALUE
    frt_bv_next_from(VALUE self, VALUE rfrom)
    {
        BitVector *bv;
        int from = FIX2INT(rfrom);
        GET_BV(bv, self);
        if (from < 0) {
            from = 0;
        }
        return INT2FIX(bv_scan_next_from(bv, from));
    }