which classes support aggregation?

[Robert Shearman]

James Hawkins wrote:

>IClassFactory->CreateInstance aggregation check: 
>"The CreateInstance method of IClassFactory takes pUnkOuter as the
>second member. This parameter must be null unless the class supports
>aggregation, which many don't."
>
>Where can I find out which classes support aggregation?
>  
>

Generally, most classes don't bother with aggregation as it is only 
something that OLE geeks get excited over. There are a few classes in 
ole32 that support aggregation and it is specified as so in MSDN. So, 
unless tests or MSDN say otherwise, just assume that a class doesn't 
support aggregation.

Rob