-static int cancelled (MPI_Status * status);
-static int get_count(MPI_Status * status, MPI_Datatype datatype);
+static int cancelled (const MPI_Status * status);
+static void set_cancelled (MPI_Status * status, int flag);
+static void set_elements(MPI_Status* status, const Datatype*, int count);
+static int get_count(const MPI_Status* status, const Datatype* datatype);