title: How to bind UISwitch to UIButton enable in RxSwift?
body: <p>I have a <code>UISwitch</code> that needs to be selected in order to continue onto the next form screen. So I would like to bind the <code>UISwitch</code> selected to the <code>UIButton</code> enabled. I just can't get this sample going.</p>
  
  <p>Here's what I'm trying but doesn't compile:</p>
  
  <pre><code>let termsValidation = termsSwitch
      .rx_selected
      .shareReplay(1)
  
  termsValidation
      .bindTo(signupButton.rx_enabled)
      .addDisposableTo(disposeBag)
  </code></pre>
  
  <p>What's the correct way to get this to work in RxSwift and RxCocoa?</p>