I agree that the if-less solution is more elegant, but I was surprised at the way it was achieved. I was expecting to see head implemented as an IntListItem. I.

I agree that the if-less solution is more elegant, but I was surprised at the way it was achieved. I was expecting to see head implemented as an IntListItem. I.e., an empty list would be just the head IntListItem, with next = NULL, and value undefined. I believe that this approach has the advantage of being clearer. Admittedly, one drawback of this approach is that it uses more space, which could be an issue in an application where you have many lists, nearly all empty.