In a Swift protocol, can you have a func parameter that is a protocol where you can swap out with a different protocol definition if it also conforms to it?

Using Swift
5

Yep, I get that. I explored using an associatedtype in the protocol as well and what I'm attempting to do also didn't work.

protocol Foo {
  associatedtype: State: ApplicationState
  func update(_ value: State)
}

This gets me the API that I want, but the call site is where it breaks down. The type I'll be passing in is some ApplicationState and casting fails.

//Rough implementation
struct FeatureContainer<Feature: Foo> {
  let feature: Foo

  func receivedUpdate(_ value: some ApplicationState) {
    feature.update(value as? Foo.State) <------ This casting will fail since the concrete type passed in is not concrete Foo.State,
    but DOES conform to the protocol that constrained ` Foo.State` (protocol UserState).
    But at this point, I don't know which `ApplicationState` protocol the `Foo.State` is using. (FreezeState or UserState).
  }
}

I guessing what I want isn't possible to accomplish since the type could have multiple protocol conformances that also conform to ApplicationState.