title: Incompatible pointer types sending 'Class' to parameter of type 'id<NSCopying>'
body: <p>I have updated xcode and now I get the error message
  Incompatible pointer types sending 'Class' to parameter of type 'id'</p>
  
  <p><pre><code>
  - (void)mapObjectClass:(Class)objectClass toCellClass:(Class)cellClass {
    [self.objectToCellMap setObject:cellClass forKey:objectClass];
  }
  </pre></code></p>
  
  <p>I would really appreciate it if someone can shed some light on this issue im having and how I can resolve it.</p>