title: type aliasing ("using") within same vs. hierarchical namespaces
body: <p>Please compare these definitions below. What is the problem with second definition? </p>
  
  <p>I want to use type1 within definition of another type in the same namespace, how should I really do that?</p>
  
  <p><strong>1st definition:</strong></p>
  
  <pre><code>namespace parent
  {
      using type1 = Int16;
  
      namespace child
      {
      using list1 = List&lt;type1&gt;; //OK!
      }
  }
  </code></pre>
  
  <p><strong>2nd definition:</strong></p>
  
  <pre><code>namespace sibling
  {
      using type1 = Int16;
      using list1 = List&lt;type1&gt;; //error: the type or namespace 'type1' could not be found.
  }
  </code></pre>
  
  <p><strong>EDIT: </strong></p>
  
  <pre><code>using type1 = Int16;
  using list1 = List&lt;type1&gt;; //error: the type or namespace 'type1' could not be found 
  
  namespace myNameSpace
  {
     using dic1 = Dictionary &lt;int, list1&gt;;
  }
  </code></pre>