An example of typeclasses with scala

TypeClass.scala

package types


object Math {

  import annotation.implicitNotFound

  @implicitNotFound("No member of type class NumberLike in scope for ${T}")
  trait NumberLike[T] {
    def plus(x: T, y: T): T

    def divide(x: T, y: Int): T

    def minus(x: T, y: T): T
  }

  object NumberLike {

    implicit object NumberLikeDouble extends NumberLike[Double] {
      def plus(x: Double, y: Double): Double = x + y

      def divide(x: Double, y: Int): Double = x / y

      def minus(x: Double, y: Double): Double = x - y
    }

    implicit object NumberLikeInt extends NumberLike[Int] {
      def plus(x: Int, y: Int): Int = x + y

      def divide(x: Int, y: Int): Int = x / y

      def minus(x: Int, y: Int): Int = x - y
    }

  }

}

object Statistics {

  import Math.NumberLike

  def mean[T](xs: Vector[T])(implicit ev: NumberLike[T]): T =
    ev.divide(xs.reduce(ev.plus), xs.size)
}