Function field

cpp/src/parquet/arrow/reader.cc:780–780

  Status GetDefLevels(const int16_t** data, int64_t* length) override;
  Status GetRepLevels(const int16_t** data, int64_t* length) override;
  const std::shared_ptr<Field> field() override { return filtered_field_; }

 private:
  const std::shared_ptr<ReaderContext> ctx_;