Is it possible to use COM smart pointers with the CList collection

Question

I'm attempting to create a CList with a COM smart pointer (one of the wrapper classes generated for _com_ptr_t) as the template parameter:

CList<IDispatchPtr, IDispatchPtr> list;

However I get several compilation errors similar to:

error C2664: 'void __stdcall SerializeElements(class CArchive &,class _com_ptr_t<class _com_IIID<struct IDispatch,&struct __s_GUID _GUID_00020400_0000_0000_c000_00000000004 6> > *,int)' : cannot convert parameter 2 from 'struct IDispatch ** ' to 'class _com_ptr_t<class _com_IIID<struct IDispatch,&struct __s_GUID _GUID_00020400_0000_0000_c000_000000000046> > *' Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast

It compiles when using regular pointers:

CList<IDispatch*, IDispatch*> list;

Looking at the MFC code that calls SerializeElements it looks like the problem is that it takes a TYPE* and there's no conversion between IDispatch** and IDispatchPtr*. Is there any way around this?

Answer 1

Because of the way operator& is overloaded, you need to wrap the smart pointers in CAdapt<>:

CList<CAdapt<IDispatchPtr>, CAdapt<IDispatchPtr> > list;