How to write an extension for NSFetchedResultsController in Swift 4

Question

I\'m trying to write a simple extension to the NSFetchedResultsController class in Swift 4.

Here\'s my first attempt - which worked in Swift 3:

Answer 1

I think I found the answer to this one. The function needs to be available to Objective-C.

Adding @objc to the func should remove the compile error. At least it did for me!