Generic type not equal in extension

Evolution Discussion
,
1

I am trying to write a little tool about Notification to convenience myself like:

private let NotificatableUserInfoKey = "Notificatable.userInfoKey"
struct Notificatable<InfoType> {
	let name: String
	fileprivate var notificationName: Notification.Name {
		Notification.Name(name)
	}
}

extension Notificatable {
	func post(object: Any? = nil, userInfo: InfoType) {
		NotificationCenter.default.post(name: notificationName, object: object, userInfo: [NotificatableUserInfoKey: userInfo])
	}
	struct InfoTypeAny {
		struct Notification {
			let name: Foundation.Notification.Name
			let object: Any?
			let userInfo: InfoType
		}
	}
	func subscribe(object: AnyObject? = nil, _ action: @escaping (_ notification: InfoTypeAny.Notification) -> Void) -> Disposable {
		
		return NotificationCenter.default.rx.notification(notificationName, object: object).subscribe(onNext: { noti in
			guard let info = noti.userInfo?[NotificatableUserInfoKey] as? InfoType else { return }
			action(.init(name: noti.name, object: noti.object, userInfo: info))
		})
	}
}

and then I want to make A extension to remove userInfo if I don't have it:

extension Notificatable where InfoType == Void {
	init(name: String) {
		self.name = name
	}
	func post(object: Any? = nil) {
		NotificationCenter.default.post(name: notificationName, object: object, userInfo: nil)
	}
	
	struct InfoTypeVoid {
		struct Notification {
			let name: Foundation.Notification.Name
			let object: Any?
		}
	}
	func subscribe(object: AnyObject? = nil, _ action: @escaping (_ notification: InfoTypeVoid.Notification) -> Void) -> Disposable {
		
		return NotificationCenter.default.rx.notification(notificationName, object: object).subscribe(onNext: { noti in
			action(.init(name: noti.name, object: noti.object))
		})
	}
}

but unfortunately it does't work, becase once you create a Notificatable, you can use 2 different subscribe function in the same time , and Swift compiler will throw you an error:

Notificatable(name: "abc").subscribe { (notification) in // Ambiguous use of 'subscribe(object:_:)'
			
}

So I think is there any possible to make extension when InfoType != Void, or just add an extension else feature by making code like:

private let NotificatableUserInfoKey = "Notificatable.userInfoKey"
struct Notificatable<InfoType> {
	let name: String
	fileprivate var notificationName: Notification.Name {
		Notification.Name(name)
	}
}
extension Notificatable where InfoType == Void {
	init(name: String) {
		self.name = name
	}
	func post(object: Any? = nil) {
		NotificationCenter.default.post(name: notificationName, object: object, userInfo: nil)
	}
	
	struct InfoTypeVoid {
		struct Notification {
			let name: Foundation.Notification.Name
			let object: Any?
		}
	}
	func subscribe(object: AnyObject? = nil, _ action: @escaping (_ notification: InfoTypeVoid.Notification) -> Void) -> Disposable {
		
		return NotificationCenter.default.rx.notification(notificationName, object: object).subscribe(onNext: { noti in
			action(.init(name: noti.name, object: noti.object))
		})
	}
} else {
	func post(object: Any? = nil, userInfo: InfoType) {
		NotificationCenter.default.post(name: notificationName, object: object, userInfo: [NotificatableUserInfoKey: userInfo])
	}
	struct InfoTypeAny {
		struct Notification {
			let name: Foundation.Notification.Name
			let object: Any?
			let userInfo: InfoType
		}
	}
	func subscribe(object: AnyObject? = nil, _ action: @escaping (_ notification: InfoTypeAny.Notification) -> Void) -> Disposable {
		
		return NotificationCenter.default.rx.notification(notificationName, object: object).subscribe(onNext: { noti in
			guard let info = noti.userInfo?[NotificatableUserInfoKey] as? InfoType else { return }
			action(.init(name: noti.name, object: noti.object, userInfo: info))
		})
	}
}