com.thoughtworks.Mixin.scala Maven / Gradle / Ivy
package com.thoughtworks
import shapeless._
trait Mixin[SuperTypes <: HList] {
type Out
}
trait LowPriorityMixin {
implicit def hconsMixin[Head, TailOut, Tail <: HList](
implicit tailMixin: Mixin.Aux[Tail, TailOut]): Mixin.Aux[Head :: Tail, Head with TailOut] =
new Mixin[Head :: Tail] {
override type Out = Head with TailOut
}
}
object Mixin extends LowPriorityMixin {
type Aux[SuperTypes <: HList, Out0] = Mixin[SuperTypes] {
type Out = Out0
}
def apply[SuperTypes <: HList](implicit mixin: Mixin[SuperTypes]): Mixin.Aux[SuperTypes, mixin.Out] = mixin
implicit def singletonMixin[Head]: Mixin.Aux[Head :: HNil, Head] = new Mixin[Head :: HNil] {
override type Out = Head
}
}