inline std::pair<int, size_t> parse_octal_number(const char *s, size_t n,
                                                 size_t i) {
  int ret = 0;
  int val;
  while (i < n && is_digit(s[i], val)) {
    ret = static_cast<int>(ret * 8 + val);
    i++;
  }
  return std::make_pair(ret, i);
}
Unknown