title: A property, indexer or dynamic member access may not be passed as an out or ref parameter
body: <p>Hello I'm having trouble figuring this out. I have these structs and classes.</p>
  
  <pre><code>struct Circle
  { ... }
  
  class Painting
  {
       List&lt;Circle&gt; circles;
  
       public List&lt;Circle&gt; circles
       {
            get { return circles; }
       }
  }
  </code></pre>
  
  <p>I am trying to modify one of the circles inside the painting class from outside it, using this code:</p>
  
  <pre><code>MutatePosition(ref painting.Circles[mutationIndex], painting.Width, painting.Height);
  </code></pre>
  
  <p>This line is giving me a compiler error:</p>
  
  <blockquote>
    <p>A property, indexer or dynamic member
    access may not be passed as an out or
    ref parameter</p>
  </blockquote>
  
  <p>Why is this, and what can I do to solve it without changing my code too much?</p>