annotation @ poly ?

[DmytroMitin]

Transforms

@poly
trait MyTypeclass[In] {
  type Out
  def foo(in: In): Out
}

into

trait MyTypeclass[In] {
  type Out
  def foo(in: In): Out
}
object MyTypeclass {
  object myTypeclassPoly extends Poly1 {
    implicit def cse(implicit mtc: MyTypeclass[In]): Case.Aux[In, mtc.Out] = at(in => mtc.foo(in))
  }
}

[DmytroMitin]

Conflicts with shapeless.poly? Rename to polymorphic, polymorph, polyFunction?

[DmytroMitin]

Implementation of @poly should be similar to @apply.