title: Swift - ReSwift Subscribe to multiple substates
body: <p>i am using ReSwift in my project to get a nice and clean redux architecture.</p>
  
  <p>As i am not interested in the whole state i just subscribe to two substates for my viewcontroller:</p>
  
  <pre><code>extension ViewController: StoreSubscriber {
  
      override func viewWillAppear(_ animated: Bool) {
          store.subscribe(self) {
              $0.select {
                  ($0.subStateA, $0.subStateB)
              }
          }
      }
  
      override func viewWillDisappear(_ animated: Bool) {
          store.unsubscribe(self)
      }
  
      func newState(state: (subStateA: SubStateA, subStateB: SubStateB)) {
          print("test")
      }
  
  }
  </code></pre>
  
  <p>What happens:</p>
  
  <p>My newState method is called every time <em>any</em> update happens to the store.</p>
  
  <p>For example if i update <em>subStateC</em> it still triggers</p>
  
  <pre><code>func newState(state: (subStateA: SubStateA, subStateB: SubStateB)) {}
  </code></pre>
  
  <p>Can anybody explain why this happens?</p>
  
  <p>Thanks and Greetings!</p>