Modifies clause error on a changed object

Question

How can I state (in Dafny) an \"ensures\" guarantee that the object returned by a method will be \"new\", i.e., will not be the same as an object used anywhere else (ye

Answer 1

You can say ensures fresh(b) on newArray.

fresh means exactly what you described: the object is not the same as any object that was allocated before the call to newArray.