+/// HungoffOperandTraits - determine the allocation regime of the Use array
+/// when it is not a prefix to the User object, but allocated at an unrelated
+/// heap address.
+/// Assumes that the User subclass that is determined by this traits class
+/// has an OperandList member of type User::op_iterator. [Note: this is now
+/// trivially satisfied, because User has that member for historic reasons.]
+///
+/// This is the traits class that is needed when the Use array must be
+/// resizable.
+