We have too few newtype/refined solutions for Scala:

• AnyVal (can be used as a new type on Scala 2/3)
• opaque type (can be used as a new type on Scala 3)
• @@ type from Scalaz (tagged type)
• @@ type from MacWire (tagged type)
• @newtype macro from NewType (estatico/scala-newtype) (newtype, Scala 2-only)
• Newtype from Newtypes (monix/newtypes) (newtype, Scala 2/3)
• NewType type from neotype (kitlangton/neotype) (newtype, Scala 3-only)
• TaggedType type from supertagged for scala (rudogma/scala-supertagged) (newtype, Scala 2-only)
• Refined from refined (fthomas/refined) (refined, Scala 2/3, but macros work only on 2)
• :| from Iron (iltotore/iron) (Scala 3-only)
• Refined from Refined4s (kevin-lee/refined4s) (refined, Scala 2/3)
• Newtype from Yet Another Newtype Library (arturaz/yantl) (Scala 3-only)