title: Destroying objects on demand with ARC
body: <p>What is the correct way to destroy an object with ARC?</p>
  
  <p>I would like to destroy a number of <code>UIViewController</code>s as well as an object holding an AUGraph at certain times during runtime.</p>
  
  <p>At the moment, when my parent viewcontroller creates viewcontroller objects and assigns their views to its <code>view</code>, the objects obviously stay alive with the parent. I would like to destroy these child viewcontrollers the moment they are not needed.</p>