Compiler Error C3702

'function' : ATL is required for COM events

You attempted to use COM events without including the necessary ATL header files.

The following sample generates C3702:

// C3702.cpp
// uncomment the following line to resolve
// #define _ATL_ATTRIBUTES 1
#include <atlbase.h>
#include <atlcom.h>
#include <atlctl.h>

[module(dll, name=idid, uuid="12341234-1234-1234-1234-123412341234")];

[object]
__interface IEvents : IUnknown
{
   HRESULT event1([in] int i);
};

[dual]
__interface IBase
{
   HRESULT fireEvents();
};

[coclass, event_source(com)]
class CEventSrc : public IBase
{
   public:
   __event __interface IEvents;

   HRESULT fireEvents()
   {
      HRESULT hr = IEvents_event1(123);
      return hr;
   }
};   // C3702

int main() {
}