Errr.
GetObjectByGUID is a free function, its not a member of CGLocalPlayer_C.
GetActivePlayer is also a free function, it calls GetObjectByGUID using the cached local player GUID as params.
Ergo, the following expression makes no sense:
GetActivePlayer()->GteObjectByGUID()
ClntObjMgrGetObjectPtr is actually just the real name for GetObjectByGUID (from the alpha).