title: What does the E2511 Type parameter 'T' must be a class type compiler error mean?
body: <p>Following my <a href="https://stackoverflow.com/questions/17730985/search-a-generic-list">previous question</a>, I am attempting to compile the code from one of the answers there.</p>
  
  <pre><code> type 
     TSearchableObjectList&lt;T&gt; = class(TObjectList&lt;T&gt;)
     end;
  </code></pre>
  
  <p>The compiler will not compile this and reports this error message:</p>
  
  <pre>
  [dcc32 Error]: E2511 Type parameter 'T' must be a class type
  </pre>
  
  <p>What does this error message mean, and how should I fix the code?</p>