Code snippet :

Main.cpp

QAXFACTORY_BEGIN((SWIQAX_FACTORY_BEGIN, SWIQAX_FACTORY_END)
QAXCLASS(Base)
QAXTYPE(D1)
QAXTYPE(D2)
QAXFACTORY_END()

Class Base {}

Class D1 : Base {}

Class D2 : D1 {}

In Client :

CComPtr<Base> B1;
CComPtr<D2> D1;
CComPtr<D2> D2;
HRESULT hr = B1->CoCreate(uuid(Base));

HRESULT hr1 = B1.QueryInterface(&D2); -> Here We are able to get memory of D2

HRESULT hr2 = B1.QueryInterface(&D1); -> Here we are not able to get the memory for D1 (NULL)
HRESULT hr3 = D2.QueryInterface(&D1); -> Here also we are not able to get the memory for D1 (NULL)

Is there any way we can get memory of D1 ? or any macro like QAXFACTORY_BEGIN will help us to get D1 memory