title: Using directive for nested type definitions
body: <p>I'm trying to use the <code>using</code> directive to define types in a functional manner to make code more readable. Let's say that my example.cs file looks like this:</p>
  
  <pre><code>using A = System.Tuple&lt;int, int&gt;;
  using B = List&lt;A&gt;;
  </code></pre>
  
  <p>I get the error:</p>
  
  <blockquote>
    <p>CS0246 The type or namespace name 'A' could not be found (are you missing a using directive or an assembly reference?)</p>
  </blockquote>
  
  <p>Can I define nested types with <code>using</code> or is it not possible?</p>