// C:\Qt\Tools\QtCreator\bin\clang\bin\clang-tidy.exe clang-tidy-ice.cpp -- -fms-extensions

// normally from <guiddef.h> via <windows.h>
typedef struct _GUID {
    unsigned long  Data1;
    unsigned short Data2;
    unsigned short Data3;
    unsigned char  Data4[ 8 ];
} GUID;

struct __declspec(uuid("00000000-0000-0000-c000-000000000046")) IUnknown;
const GUID IID_IUnknown = {0x00000000, 0x0000, 0x0000, {0xC0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x46}};

using REFGUID =const GUID &;
bool IsEqualGUID(REFGUID rguid1, REFGUID rguid2);

template<const GUID * _IID> void template_uuid() {
#if 0
	//ATL/comsuppp tend to be either comparing the GUID
	if(IsEqualGUID(*_IID,IID_IUnknown)) {

	}
#elif 0
	// or copying it for runtime use after type-erasure
	GUID iid = *_IID;
#else
	// but neither seems to be necessary. While this produces "warning: expression result unused" (as expected)
	// for IID_IUnknown, mentioning the parameter in any way even unused and not dereferenced,
	// seems to be  enough to provoke the crash when using __uuidof
	_IID;
#endif

}

void foo() {
#if 1
	template_uuid<&_uuidof(IUnknown)>();
#else
	template_uuid<&IID_IUnknown>();
#endif
}