Is it possible to automatically load the php classes in the Drupal 8 themes folder?

Does the namespace, the name of the class and the naming convention work the same as for the modules?

These links do not seem to mention it.

https://www.drupal.org/docs/develop/standards/psr-4-namespaces-and-autoloading-in-drupal-8

https://www.drupal.org/node/2349803