I admit that I am not an expert on Scala, but I am confused about your "Person" example. I thought that this was exactly the common use case that wouldn't cost

I admit that I am not an expert on Scala, but I am confused about your "Person" example. I thought that this was exactly the common use case that wouldn't cost you an allocation. According to http://docs.scala-lang.org/overviews/core/value-classes.html http://docs.scala-lang.org/overviews/core/value-classes.html: A value class is actually instantiated when: a value class is treated as another type. a value class is assigned to an array. doing runtime type tests, such as pattern matching. none of which is the case in the example.