The Old New Thing

Can CoCreateGuid ever return GUID_NULL?

March 26, 2014 Mar 26, 2014 03/26/14

Raymond Chen

A customer asked whether the function can ever return . Their code uses for special purposes, and it would be bad if that was ever returned as the GUID for an object. "Can we assume that never returns ? Or should we test the return value against , and if it is equal, then call and try again?" Some people started running a bunch of times ...