Swift: Cannot assign to immutable expression of type 'AnyObject?!'

Question

I searched, but I didn\'t find a familiar answer, so...

I am about to program a class to handle parse methods like updating, adding, fetching and deleting.

Answer 1

In swift a lot of types are defined as structs, which are immutable by default.

I had the same error doing this :

protocol MyProtocol {
    var anInt: Int {get set}
}

class A {

}

class B: A, MyProtocol {
    var anInt: Int = 0
}

and in another class :

class X {

   var myA: A

   ... 
   (self.myA as! MyProtocol).anInt = 1  //compile error here
   //because MyProtocol can be a struct
   //so it is inferred immutable
   //since the protocol declaration is 
   protocol MyProtocol {...
   //and not 
   protocol MyProtocol: class {...
   ...
}

so be sure to have

protocol MyProtocol: class {

when doing such casting