Advantages over AnyVal?

[CremboC]

The README.md compares this library to Haskell's newtype and to Tagged types. However, more crucially, it doesn't mention how this is any different/better than simply using case class Thing(value: String) extends AnyVal.

From my understand this is an alternative to extends AnyVal, hence this info is crucial.

[markschaake]

See https://docs.scala-lang.org/overviews/core/value-classes.html

[barambani]

@CremboC you might also find this

https://failex.blogspot.com/2017/04/the-high-cost-of-anyval-subclasses.html

and this

https://github.com/barambani/http4s-extend#new-type

interesting on the subject.