Build
-----

```
$ cd cpp
$ qmake lib.pro
$ make
$ cd ..
```


Run
---

```
$ lqml ~/slime/qml-start-swank.lisp
$ emacs run.lisp
```

After `M-x slime-connect` and loading `run.lisp`, you can see that, despite
the argument and return type simply being defined as `QVariant`, you may also
pass lists, because a `QVariant` can also be of type `QVariantList`, so this
is a perfect fit for (nested) Lisp lists.

So, we pass a nested Lisp list, and it gets shown on Qt side with the
respective types. Then the `QVariantList` is returned to Lisp, where it is
automatically converted back to a nested Lisp list.

Really convenient!