Re: error C2898: HRESULT IUnknown::QueryInterface(Q**p) : member function templates cannot be virtual

From:

"Igor Tandetnik" <itandetnik@mvps.org>

Newsgroups:

microsoft.public.vc.atl

Date:

Tue, 21 Aug 2007 07:49:31 -0400

Message-ID:

<#41NYl#4HHA.5796@TK2MSFTNGP05.phx.gbl>

"tom" <kamildobk@poczta.onet.pl> wrote in message
news:1187687316.394719.36230@w3g2000hsg.googlegroups.com

I try to move all C-based interfaces in my application to COM. I
changed

class IMyIf
{
virtual void Foo() = 0;
}

to:

#include"unknwn.h"

__interface IMyIf : IUnknown
{
virtual void Foo() = 0;
}

but when I try to compile simple console based application with this
interface I get following error

error C2898: HRESULT IUnknown::QueryInterface(Q**p) : member function
templates cannot be virtual

Just make it

struct IMyIf : public IUnknown {
STDMETHOD(Foo)() = 0;
};

Better still, define your interfaces in an IDL file and use
MIDL-generated header.
--
With best wishes,
Igor Tandetnik

With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going to
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925