Method HasValue

cpp/src/arrow/util/iterator.h:237–237

      : finished_(finished), ready_for_next_(ready_for_next), yield_value_() {}

  bool HasValue() const { return yield_value_.has_value(); }
  bool Finished() const { return finished_; }
  bool ReadyForNext() const { return ready_for_next_; }
  T Value() const { return *yield_value_; }