Write the value of the specified rhs object to the specified output stream in a single‐line format, and return a reference to the modifyable stream. If stream is not valid on entry, this operation has no effect. Note that this human‐readable format is not fully specified, can change without notice, and is logically equivalent to: ` print(stream, 0, ‐1); ` Single line output format for the DatumUdt object is shown below: ` user‐defined(<address>,type) ` (where address is hex value of the pointer to the user‐define object and type is the type of the user‐defined object)