title: Unqualified lookup and (maybe-)dependent base classes
body: <p>Consider the following program:</p>
  
  <pre><code>template &lt;typename T&gt;
  struct t
  {
      struct base { void f1(); };
      struct derived : base
      {
          void f2()
          {
              f1();
          }
      };
  };
  </code></pre>
  
  <p>In <code>derived::f2</code>, unqualified lookup is used to find <code>f1</code>. Will <code>base</code> be searched? Will <code>base::f1</code> be found? Is <code>base</code> a dependent type?</p>
  
  <p>Please substantiate your answers with quotes from the standard.</p>