template <typename CtorSignature, typename UniqueIdType> class ObjectFactory;


template<typename BaseClassType, typename ClassType>
BaseClassType CreateObject()
{
   return new ClassType();
}

template<typename BaseClassType, typename UniqueIdType>
class ObjectFactory<BaseClassType (), UniqueIdType>
{
protected:
   typedef BaseClassType (*CreateObjectFunc)();

public:
   ...
   BaseClassType Create(UniqueIdType unique_id)
   {
      ...
      return ((*iter).second)();
   }
   ...
protected:
   ...
};


template<typename BaseClassType, typename Param1Type, typename ClassType>
BaseClassType CreateObject(Param1Type param1)
{
   return new ClassType(param1);
}

template<typename BaseClassType, typename Param1Type, typename UniqueIdType>
class ObjectFactory<BaseClassType (Param1Type), UniqueIdType>
{
protected:
   typedef BaseClassType (*CreateObjectFunc)(Param1Type);

public:
   ...
   BaseClassType Create(UniqueIdType unique_id, Param1Type param1)
   {
      ...
      return ((*iter).second)(param1);
   }
   
   ...
protected:
   ...
};


template<typename BaseClassType, typename Param1Type, typename Param2Type, typename ClassType>
BaseClassType CreateObject(Param1Type param1, Param2Type param2)
{
   return new ClassType(param1, param2);
}

template<typename BaseClassType, typename Param1Type, typename Param2Type, typename UniqueIdType>
class ObjectFactory<BaseClassType (Param1Type, Param2Type), UniqueIdType>
{
protected:
   typedef BaseClassType (*CreateObjectFunc)(Param1Type, Param2Type);

public:
   ...
   BaseClassType Create(UniqueIdType unique_id, Param1Type param1, Param2Type param2)
   {
      ...
      return ((*iter).second)(param1, param2);
   }
   
   ...
protected:
   ...
};