CHECK: SAXPY (functor method)
CHECK-NEXT: 2 * 1 + 1 = 3
CHECK-NEXT: 2 * 2 + 1 = 5
CHECK-NEXT: 2 * 3 + 1 = 7
CHECK-NEXT: 2 * 4 + 1 = 9
CHECK-NEXT: SAXPY (placeholder method)
CHECK-NEXT: 2 * 1 + 1 = 3
CHECK-NEXT: 2 * 2 + 1 = 5
CHECK-NEXT: 2 * 3 + 1 = 7
CHECK-NEXT: 2 * 4 + 1 = 9