title: Use a generic class as a custom view in Interface Builder
body: <p>I have a custom subclass of UIButton:</p>
  
  <pre><code>import UIKit
  
  @IBDesignable
  class MyButton: UIButton {
  
      var array : [String]?
  
  }
  </code></pre>
  
  <p>It is IBDesignable and I have set it as the custom class for one of the buttons in my storyboard. I would like to make it generic so that the array does not have to be one of String objects. So, I tried this:</p>
  
  <pre><code>import UIKit
  
  @IBDesignable
  class MyButton&lt;T&gt;: UIButton {
  
      var array : [T]?
  
  }
  </code></pre>
  
  <p>However, I am unsure how to set this as the class now in IB. I tried putting <code>MyButton&lt;String&gt;</code> or <code>MyButton&lt;Int&gt;</code>, but Interface Builder just removes the angle brackets portion and gets the following compile error:</p>
  
  <pre><code>Command /Applications/Xcode6-Beta4.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift failed with exit code 254
  </code></pre>
  
  <p>Is there a way to use a generic custom class, or is it not supported?</p>