/// info

Keep in mind that dataclasses can't do everything Pydantic models can do.

So, you might still need to use Pydantic models.

But if you have a bunch of dataclasses laying around, this is a nice trick to use them to power a web API using FastAPI. 🤓

///

## Dataclasses in `response_model`

You can also use `dataclasses` in the `response_model` parameter:

/// tip

This is just standard Python, it's called a "type alias", it's actually not specific to **FastAPI**.

But because **FastAPI** is based on the Python standards, including `Annotated`, you can use this trick in your code. 😎

///

      sort(
          insertionOrder,
          new Comparator<V>() {
            @Override
            public int compare(V left, V right) {
              // The indexes are small enough for the subtraction trick to be safe.
              return indexOfEntryWithValue(left) - indexOfEntryWithValue(right);
            }

            int indexOfEntryWithValue(V value) {
              for (int i = 0; i < orderedEntries.size(); i++) {