Read/write C++ built-in types to/from TDirectory

How does one do this, e.g. for an unsigned long? The two TDirectory::WriteObjectAny() functions require either a class name or a pointer to a TClass object. TDirectory::WriteObject() seems appropriate, but the TDirectory source file comments that it is “intentionally not implemented.” The source file also mentions template <class T> inline Int_t WriteObject(const T* obj, const char* name, Option_t *option="", Int_t bufsize=0)but a call to that fails with the message [quote]“unknown type for , it cannot be written”[/quote] That failure occurs whether one specifies the template arg, e.g.WriteObject<unsigned long>(&MyNumber, "MyNumber"); or leaves it for the compiler to deduce. TDirectory’s other write functions all require a descendant of TObject. I must be missing something…

[EDIT} System: Yosemite (10.10.1), ROOT6 (HEAD of master branch, which I update ~daily)