title: Pass a protocol as a method argument
body: <p>First let me explain what I don't mean. I don't want to type an argument to a protocol:</p>
  
  <pre><code>-(void)someMethod:(id&lt;SomeProtocol&gt;)someArgument;
  </code></pre>
  
  <p>What I do want to is to pass a protocol to a method in the same way I can pass a Class to a method (The following is incorrect, but it hopefully explains what I want to do):</p>
  
  <pre><code>-(void)someMethod:(Protocol)someArgument;
  </code></pre>
  
  <p>I would then like to be able to use the Protocol to check whether a set of objects implement it.</p>