| Argument | Type | Description |
| pstm | IStream * | The stream from which the object should be unmarshaled. |
| iid | REFIID | The interface with which we want to talk to the reconstituted object. |
| ppv | void ** | The place in which we should return the interface pointer. |
| return value | HRESULT | S_OK, E_FAIL, E_NOINTERFACE |