title: Type "T?" does not conform to protocol 'Equatable'
body: <p>I have a generic class similar to this one:</p>
  
  <pre><code>class C&lt;T: Equatable&gt; {
  
      let t: T
  
      init(t: T) { 
          self.t = t
      }
  
  }
  </code></pre>
  
  <p>When I try to wrap <code>Int?</code> inside, I get the following error:</p>
  
  <pre><code>// ERROR: Type "Int?" does not conform to protocol 'Equatable'
  let c = C&lt;Int?&gt;(t: nil)
  </code></pre>
  
  <p>A quick test shows that <code>Int?</code> indeed is <code>Equatable</code>:</p>
  
  <pre><code>let a: Int? = 5
  let b: Int? = 6
  
  let c = a == b // NO ERROR
  </code></pre>
  
  <p>Maybe I'm just too tired today?</p>