Publisher/Subscriber Pattern from C# to Swift

Publisher-Subscriber in C#

using System.Collections.Generic;

interface IPublisher<T> {
	void Subscribe(ISubscriber<T> subscriber);
}

interface ISubscriber<T> {
	void Publish(T value);
}

class Subject<T>: IPublisher<T>, ISubscriber<T> {
	private List<ISubscriber<T>> subscribers = new List<ISubscriber<T>>();

	public void Subscribe(ISubscriber<T> subscriber) {
		this.subscribers.Add(subscriber);
	}

	public void Publish(T value) {
		foreach (var subscriber in this.subscribers) {
			subscriber.Publish(value);
		}
	}
}

Publisher-Subscriber in Swift

protocol SubscriberType {
	typealias Element
	func publish(value: Element)
}

protocol PublisherType {
	typealias Element
	func subscribe<S: SubscriberType where S.Element == Element>(subscriber: S)
}

class Subject<T>: SubscriberType, PublisherType {
	typealias Element = T

	// Can't define a list of any subscribers of T
	private var subscribers: [SubscriberType] = []
	
	func subscribe<S : SubscriberType where S.Element == Element>(subscriber: S) {
		subscribers.append(subscriber)
	}
	
	func publish(value: T) {
		for subscriber in subscribers {
			subscriber.publish(value)
		}
	}
}