rv = rv.Slice3(4, 4, 4)
	ptr3 := rv.UnsafePointer()
	if ptr3 != ptr2 {
		t.Errorf("xs.Slice3(3,5,7).Slice3(4,4,4).UnsafePointer() = %p, want %p", ptr3, ptr2)
	}
}

func TestSetLenCap(t *testing.T) {
	xs := []int{1, 2, 3, 4, 5, 6, 7, 8}
	xa := [8]int{10, 20, 30, 40, 50, 60, 70, 80}

	vs := ValueOf(&xs).Elem()
	shouldPanic("SetLen", func() { vs.SetLen(10) })