Method Next

cpp/src/arrow/util/iterator.h:116–126

\brief Return the next element of the sequence, IterationTraits ::End() when the iteration is completed.

  /// \brief Return the next element of the sequence, IterationTraits<T>::End() when the
  /// iteration is completed.
  Result<T> Next() {
    if (ptr_) {
      auto next_result = next_(ptr_.get());
      if (next_result.ok() && IsIterationEnd(next_result.ValueUnsafe())) {
        ptr_.reset(NULLPTR);
      }
      return next_result;
    } else {
      return IterationTraits<T>::End();
    }
  }

  /// Pass each element of the sequence to a visitor. Will return any error status
  /// returned by the visitor, terminating iteration.