Function mutable_data

cpp/src/arrow/compute/row/row_internal.h:264–270

    return NULLPTR;
  }
  uint8_t* mutable_data(int i) {
    ARROW_DCHECK(i >= 0 && i < kMaxBuffers);
    if (ARROW_PREDICT_TRUE(buffers_[i])) {
      return buffers_[i]->mutable_data();
    }
    return NULLPTR;
  }

  /// \brief Resize the fixed length buffers to store `num_extra_rows` more rows. The
  /// fixed length buffers are buffers_[0] for null masks, buffers_[1] for row data if the