title: performSelector:withObject:, but not with an object
body: <p>I want to do performSelector:withObject: but where the object is a CGFloat. So it's not actually an object. How can I do this?</p>
  
  <p>the object I am performing the selector on is not mine, I can't modify it.</p>
  
  <p>eg</p>
  
  <pre><code>[xyz performSelector:@selector(setOffset:) withObject:2];
  </code></pre>
  
  <p>(after posting I changed what I need to slightly to this:</p>
  
  <pre><code>[xyz performSelector:@selector(setOffset:) withObject:CGSizeMake(2,0)];
  </code></pre>