class _declspec(dllexport) GeoVectorProperty
{
public:
   virtual void setValue(int y, unsigned int idx);
};

template<typename X>
class TypedGeoVectorProperty : public GeoVectorProperty
{
public:
   void setValue(X n, unsigned int idx);

   template<typename Y>
   void setValue(Y y, unsigned int idx) {;}
};

// 1) Rename helper method GeoVectorProperty::setValue() to something else.
// 2) Make GeoVectorProperty::setValue() non-virtual.