title: Swift tuple declaration in a protocol
body: <p>I have a tuple variable in my code, that comes from ReactiveSwift:</p>
  
  <pre><code>class MyClass {
     var (signal, signalSender) = Signal&lt;Bool, Error&gt;.pipe()
  }
  </code></pre>
  
  <p>How can I declare that variable tuple in a protocol?</p>
  
  <p>Similar like this (doesn't work):</p>
  
  <pre><code>protocol MyProtocol {
     var (signal, signalSender): Signal&lt;Bool, Error&gt; { get set }
  }
  </code></pre>
  
  <p>There appears a syntax error: <em>"Getter/setter can only be defined for a single variable"</em></p>
  
  <p>Thank you!</p>