title: C++ Override Syntax
body: <p>I'm working with Intel's PCSDK, there's a part I don't syntactically understand from a sample where the constructor of an abstract class is overridden. Specifically, this line:</p>
  
  <pre><code>GesturePipeline (void):UtilPipeline(),m_render(L"Gesture Viewer") {
  EnableGesture();
  }
  </code></pre>
  
  <p>What does the comma between UtilPipeline() and m_render mean? Here's the entire code for context: </p>
  
  <pre><code>#include "util_pipeline.h"
  #include "gesture_render.h"
  #include "pxcgesture.h"
  class GesturePipeline: public UtilPipeline {
  public:
  GesturePipeline (void):UtilPipeline(),m_render(L"Gesture Viewer") {
  EnableGesture();
  }
  virtual void PXCAPI OnGesture(PXCGesture::Gesture *data) {
  if (data-&gt;active) m_gdata = (*data);
  }
  virtual void PXCAPI OnAlert(PXCGesture::Alert *data) {
  switch (data-&gt;label) {
  case PXCGesture::Alert::LABEL_FOV_TOP:
  wprintf_s(L"******** Alert: Hand touches the TOP boundary!\n");
  break;
  case PXCGesture::Alert::LABEL_FOV_BOTTOM:
  wprintf_s(L"******** Alert: Hand touches the BOTTOM boundary!\n");
  break;
  case PXCGesture::Alert::LABEL_FOV_LEFT:
  wprintf_s(L"******** Alert: Hand touches the LEFT boundary!\n");
  break;
  case PXCGesture::Alert::LABEL_FOV_RIGHT:
  wprintf_s(L"******** Alert: Hand touches the RIGHT boundary!\n");
  break;
  }
  }
  virtual bool OnNewFrame(void) {
  return m_render.RenderFrame(QueryImage(PXCImage::IMAGE_TYPE_DEPTH),
  QueryGesture(), &amp;m_gdata);
  }
  protected:
  GestureRender m_render;
  PXCGesture::Gesture m_gdata;
  };
  </code></pre>