#includeIn this example, we declare a pointer to an IUnknown object called pItem. We then call the GetGUID method on the pItem object, passing in the GUID_Item parameter and a pointer to a GUID variable called guid. The GetGUID method returns an HRESULT indicating whether the operation was successful or not. Based on the syntax and usage of the GetGUID method, it seems likely that it is part of the Windows API package library, as it is a system-level function that provides access to system-level objects and components.// declare the item IUnknown *pItem = ....; // get the GUID GUID guid; HRESULT hr = pItem->GetGUID(GUID_Item, &guid); // check for errors and use the GUID if (SUCCEEDED(hr)) { // use the GUID }