title: differences between StringBuilder in Java and C#
body: <p>I am converting Java code to C#. The StringBuilder class in Java seems to have many more methods than the C# one. I am interested in (say) the Java functionality</p>
  
  <pre><code>sb.indexOf(s);
  sb.charAt(i);
  sb.deleteCharAt(i);
  </code></pre>
  
  <p>which seems to be missing in C#.</p>
  
  <p>I suppose the first two could be modelled by</p>
  
  <pre><code>sb.ToString().IndexOf(s);
  sb.ToString().CharAt(i);
  </code></pre>
  
  <p>but would the third operate on a copy of the contents of the sb rather than the actual contents?</p>
  
  <p>Is there a common way of adding this functionality to all missing methods?</p>