Handle to generic protocol conforming type

GenericProtocolHandle.swift

protocol PresentationItem { }

protocol AnyPresenter {
    func _present(item: Any) -> Void
}

protocol Presenter: AnyPresenter {
    typealias PresentationType
    
    func present(item: PresentationType) -> Void
}

extension Presenter {
    func _present(state: Any) -> Void {
        if let typed = state as? PresentationType {
            present(typed)
        }
    }
}

struct UserPresentationItem : PresentationItem { }

class View : Presenter {
    
    func present(item: UserPresentationItem) {
        // Use item...
    }
    
}

let presenter = View()
let anyPresenter: AnyPresenter = presenter

anyPresenter._present(UserPresentationItem())