//  Helper

func printClass(_ klass: NSObject.Type) {
    print(NSClassFromString(klass.className()))
}

//  Nested declaration of generic NSObject subclass. Fails:

({
    class NestedGenericNSObjectSubclass<T>: NSObject { }

    printClass(NestedGenericNSObjectSubclass<Int>.self) // nil
})()

//  Top-level declaration of generic NSObject subclass +
//  nested declaration of type. Fails:

class TopLevelGenericNSObjectSubclass<T>: NSObject { }

({
    enum SomeNestedType { }

    printClass(TopLevelGenericNSObjectSubclass<SomeNestedType>.self) // nil
})()

//  Works:

printClass(TopLevelGenericNSObjectSubclass<Int>.self) // TopLevelGenericNSObjectSubclass<Int>