/*
 *  call-seq:
 *     bv.next_unset_from(from) -> bit_num
 *  
 *  Returns the next unset 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 unset it will
 *  return the number 10. If the bit vector has not been negated than you
 *  should use the +#next_from+ method.
 */
VALUE
frt_bv_next_unset_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_unset_from(bv, from));
}