8 ms·

Haskell's typeclass provide it.

• dragonwriter 12y ago
  Typeclasses aren't structural typing, they are nominative typing, as typing is controlled by explicit declaration of relations between types and typeclasses, not inferred from structural properties.
  • tel 12y ago
    Sure they are: (forall a. X a => a) is a supertype of (forall a. (X a, Y a) => a).
    • dragonwriter 12y ago
      I stand corrected.