title: error C3646: 'closure' : unknown override specifier
body: <p><strong>I got the following error:</strong></p>
  
  <pre><code>error C3646: 'closure' : unknown override specifier
  </code></pre>
  
  <p><strong>The code:</strong></p>
  
  <pre><code>void BaseOperator::mousebutton_cb(EventObject* sender, EventArgs* calldata, void* closure)
  {
      xd3D::Operation::Operator::BaseOperator* operator = (xd3D::Operation::Operator::BaseOperator*)closure;
      MouseButtonEventArgs* e = (MouseButtonEventArgs*)calldata;
      if (e-&gt;Status == Down)
          operator-&gt;OnMouseButtonDown(e);
      else
          operator-&gt;OnMouseButtonUp(e);
  }
  </code></pre>
  
  <p>Do you know why I have this error?</p>