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ATL Provider Error ATL2056

Derive from either class1 or class2, not both.

The class is derived from two incompatible classes. To resolve, remove the derivation from either class1 or class2.

The following sample generates ATL2056.

// ATL2056.cp
// compile with: /c
// ATL2056 expected
#include <atlbase.h>
#include <atlcom.h>

[ dual ]
__interface IATL2056 : IDispatch
   HRESULT Method1();

[ coclass ]
class CATL2056 : public IDispatchImpl<IATL2056>
   public IATL2056 // to resolve, comment this line out
   public :
   HRESULT Method1()
      return S_OK;