C / C++ / MFC

class CCoImpl : public IFun, public ITest
{
   HRESULT QueryInterface()
   {
      if (iid == IUnknown) {  // always return the same pointer when specifically asked for IUnk; which one doesn't matter
        addref, return static_cast<IFun *>(this);
      }
      if (iid == IFun) {
        addref, return static_cast<IFun *>(this); 
      }
      if (iid == ITest) {
        addref, return static_cast<ITest *>(this);
      }
     return E_NOINTERFACE;
   }
   // IFun methods:
   HRESULT GoShopping() { ... }
   HRESULT GoRocking()  { ... }

   // ITest Methods
   HRESULT TestCountShoes(....) { ... }
};