duplicates:

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

Issue Description:

If I have a struct that conforms to a protocol and I pass it into Obj-C and get it back out again, I end up with a _SwiftValue stored in an Any. This by itself seems problematic, because it should only need the _SwiftValue wrapper when stored in an AnyObject, but casting back to the source type works. However, casting to a protocol breaks. If I first cast the value to AnyObject, then casting to a protocol works.

Example:

import Foundation

protocol Foo {
    func bar()
}

struct MyStruct: Foo {
    func bar() {}
}

let ary = NSMutableArray()
ary.add(MyStruct())
let x = ary.firstObject!
print(type(of: x)) // prints _SwiftValue
print(x is Foo) // prints false
print(x as AnyObject is Foo) // prints true
print((x as AnyObject) as Any is Foo) // prints false