Make it easy to log custom arrow data in C++

[Wumpf]

Related

• Fixes Implement AnyValues for C++ #8835

What

Adds a few small utilities to ComponentBatch & ComponentColumn to make logging with raw arrow arrays more convenient.
Adds snippets that are on par with the other sdks demonstrating how "any value"-style logging can be done

Example for mixing points with fully custom arrow values:

    auto points = rerun::Points2D({{-1.0f, -1.0f}, {-1.0f, 1.0f}, {1.0f, -1.0f}, {1.0f, 1.0f}});

    std::shared_ptr<arrow::Array> arrow_array;
    arrow::DoubleBuilder confidences_builder;
    ARROW_RETURN_NOT_OK(confidences_builder.AppendValues({0.3, 0.4, 0.5, 0.6}));
    ARROW_RETURN_NOT_OK(confidences_builder.Finish(&arrow_array));
    auto confidences =
        rerun::ComponentBatch::from_arrow_array(std::move(arrow_array), "confidence");

    rec.log("extra_values", points, confidences);

---

• pass main ci

[github-actions]

Web viewer built successfully. If applicable, you should also test it:

• I have tested the web viewer

Result	Commit	Link	Manifest
✅	0839fc4	https://rerun.io/viewer/pr/8880	+nightly +main

^{Note: This comment is updated whenever you push a commit.}

[teh-cmc]

I'm taking a chance and triggering the full-check early...

Advienne que pourra

[teh-cmc]

@rerun-bot full-check

[github-actions]

Started a full build: https://github.com/rerun-io/rerun/actions/runs/13076163029

[teh-cmc]

looks pretty based to me

[teh-cmc]

✨

[teh-cmc]

You can add the failing links to the growing collection at the bottom of lychee.toml 🙃

* [404] [https://github.com/rerun-io/rerun/blob/main/docs/snippets/all/howto/any_values_send_columns.cpp](https://github.com/rerun-io/rerun/blob/main/docs/snippets/all/howto/any_values_send_columns.cpp) | Failed: Network error: Not Found
* [404] [https://github.com/rerun-io/rerun/blob/main/docs/snippets/all/tutorials/any_values.cpp](https://github.com/rerun-io/rerun/blob/main/docs/snippets/all/tutorials/any_values.cpp) | Failed: Network error: Not Found
* [404] [https://github.com/rerun-io/rerun/blob/main/docs/snippets/all/tutorials/extra_values.cpp](https://github.com/rerun-io/rerun/blob/main/docs/snippets/all/tutorials/extra_values.cpp) | Failed: Network error: Not Found
* [404] [https://github.com/rerun-io/rerun/blob/main/docs/snippets/all/howto/any_batch_value_send_columns.cpp](https://github.com/rerun-io/rerun/blob/main/docs/snippets/all/howto/any_batch_value_send_columns.cpp) | Failed: Network error: Not Found

[teh-cmc]

Failing on windows!

[teh-cmc]

@rerun-bot full-check

[github-actions]

Started a full build: https://github.com/rerun-io/rerun/actions/runs/13077120061

[Wumpf]

thanks!