title: What's the point of a final virtual function?
body: <p><a href="http://en.wikipedia.org/wiki/C%2B%2B11#Explicit_overrides_and_final">Wikipedia</a> has the following example on the C++11 final modifier:</p>
  
  <pre><code>struct Base2 {
      virtual void f() final;
  };
  
  struct Derived2 : Base2 {
      void f(); // ill-formed because the virtual function Base2::f has been marked final
  };
  </code></pre>
  
  <p>I don't understand the point of introducing a virtual function and immediately marking it as final. Is this simply a bad example, or is there more to it?</p>