duplicates:

• SR-3871 Protocol passing via objective-c / Any can't be cast back to protocol type

Issue Description:

I found out a very strange issue which is happening when calling the `performSegue` method in UIKit

I have a structure like following

protocol MyProtocol {}

struct MyStruct: MyProtocol {}

By passing the structure as sender in the performSegue like following
`vc.performSegue(withIdentifier: "id", sender: myStructInstance)`

In the `preparForSegue` method, the sender instance cannot be converted to `MyProtocol`

sender! is MyProtocol // return false
sender as! MyProtocol // crashes
sender! is MyStruct // return true
sender as! MyStruct // return true

I fixed this problem by wrapping `MyProtocol` inside an another structure and then I can easily access the value as below

struct Wrapper {
    let myProtocol: MyProtocol
}

(sender as! Wrapper).myProtocol is MyProtocol // return true