How to use gestures with SDL 2 on iOS

I’m looking for equivalents of UISwipeGestureRecognizer, UIRotationGestureRecognizer and UIPinchGestureRecognizer.
It is possible according to but very poorly documented (and the test app is also too basic to be useful).
Somebody posted here a more complete example, but with a big warning that “there is no API to prevent the mouse events so I have hacked the mouse events … watch future SDL 1.3 releases”: