Method Next

cpp/src/arrow/util/iterator.h:278–287

        finished_() {}

  Result<V> Next() {
    while (!finished_) {
      ARROW_ASSIGN_OR_RAISE(std::optional<V> next, Pump());
      if (next.has_value()) {
        return std::move(*next);
      }
      ARROW_ASSIGN_OR_RAISE(last_value_, it_.Next());
    }
    return IterationTraits<V>::End();
  }

 private:
  // Calls the transform function on the current value.  Can return in several ways