if x != int64(r) {
		s.errorString("overflow on character value " + string(r))
	}
	return int64(r)
}

// scanBasePrefix reports whether the integer begins with a base prefix
// and returns the base, digit string, and whether a zero was found.
// It is called only if the verb is %v.
func (s *ss) scanBasePrefix() (base int, digits string, zeroFound bool) {
	if !s.peek("0") {
		return 0, decimalDigits + "_", false
	}