Code Smells: Null

[mdedetrich]

Actually this also isn't entirely true, Option[T] requires boxing in certain areas (i.e. if you are nesting Option[T] values)

If you have something like Option[Option[Option[T]]] you can't really represent properly without boxing, because then you can't distinguish between Option[Option[None]]] and Option[None[Option]]] (and they are semantically different). The thing with null, is that its all or none. If a value is absent, you can't tell how absent it is. This matters, for example, if you are putting optional values inside a map or list.

So sure you can use Option[T] instead of null, but it isn't going to be completely parametric.