 }
 
 /// A disposable that will optionally dispose of another disposable.
-class SerialDisposable: Disposable {
+@final class SerialDisposable: Disposable {
 	struct _State {
 		var innerDisposable: Disposable? = nil
 		var disposed = false

}

/// A disposable that will run an action upon disposal.
class ActionDisposable: Disposable {
	var _action: Atomic<(() -> ())?>

	var disposed: Bool {

}

/// A disposable that will dispose of any number of other disposables.
@final class CompositeDisposable: Disposable {
	var _disposables: Atomic<Disposable[]?>
	
	var disposed: Bool {
