Method CreateUnionTypeCodes

cpp/src/arrow/array/util.cc:846–851

  }

  Result<std::shared_ptr<Buffer>> CreateUnionTypeCodes(int8_t type_code) {
    TypedBufferBuilder<int8_t> builder(pool_);
    RETURN_NOT_OK(builder.Resize(length_));
    builder.UnsafeAppend(length_, type_code);
    return builder.Finish();
  }

  template <typename OffsetType>
  Status CreateOffsetsBuffer(OffsetType value_length, std::shared_ptr<Buffer>* out) {