Re: COM Errors not using ISupportErrorInfoImpl

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From: Igor Tandetnik (itandetnik_at_mvps.org)
Date: 09/07/04 

Date: Tue, 7 Sep 2004 13:43:58 -0400

"Brian Muth" <bmuth@mvps.org> wrote in message
news:uU73cFQlEHA.1244@TK2MSFTNGP15.phx.gbl
> "Mitch Marcus" <mmarcus@book.com> wrote in message
> news:e7J9E2PlEHA.3428@TK2MSFTNGP11.phx.gbl...
>> What I wanted to do was to have one ATL class that gets instantiated
>> by two different interfaces. The reason for this is was to support
>> existing clients and provide an enhanced interface for new clients.
>> I figured I could have two interfaces to one class.
>
> You can certainly do exactly this with a single ATL class. You will
> need to manually define the second interface in your IDL, and add the
> interface to the multiple inheritance list, and your
> BEGIN_COM_MAP..END_COM_MAP, but that's about it. Define the
> methods/properties in your header file and then go to town and
> implement...

But beware multiple dual interfaces on the same object. See
http://www.mvps.org/vcfaq/com/9.htm 

-- 
With best wishes,
    Igor Tandetnik
"On two occasions, I have been asked [by members of Parliament], 'Pray,
Mr. Babbage, if you put into the machine wrong figures, will the right
answers come out?' I am not able to rightly apprehend the kind of
confusion of ideas that could provoke such a question." -- Charles
Babbage

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