title: Two ways to declare template friend classes?
body: <pre><code>template&lt;typename T&gt; class FooBar {};
  
  template&lt;typename T&gt; class Bar {
      friend class FooBar&lt;T&gt;;
  };
  
  template&lt;typename T&gt; class Bar2 {
      template friend class FooBar&lt;T&gt;;
  };
  </code></pre>
  
  <p>What is the difference between class Bar and Bar2?</p>