Method to_csv

src/csv/csv.cpp:18–43

			const auto& vec = chunk.vecs[col_id].get();
			visit(overloaded {[&]<typename PT>(const up<TypedVector<PT>>& typed_vector) {
				                  stream << typed_vector->m_data[row_id];
			                  },
			                  [](auto&) {
				                  FLS_UNREACHABLE();
			                  }},
			      vec);

			if (col_id < chunk.vecs.size() - 1) { stream << "|"; };
			if (col_id == chunk.vecs.size() - 1) { stream << "\n"; };
		};
	}
	File::write(file_path, stream.str());
}
} // namespace fastlanes