title: how can i modify a value in list<t>?
body: <pre><code>    class SomeClass
      {
  
          private struct PhraseInfo
          {
              public int Start;
              public int Length;
          }
  
  ...
  
          private void SomeMethod(...)
          {
              List&lt;PhraseInfo&gt; posesBracket = new List&lt;PhraseInfo&gt;();
              posesBracket.Add(new PhraseInfo());
              posesBracket[0].Start = 10;
          }
  </code></pre>
  
  <p>of cause, posesBracket[0].start=10; occur compiler error CS1612 : "Cannot modify the return value of 'expression' because it is not a variable"</p>
  
  <p>how can i modify a value in list?</p>