Playing with typeclasses in Scala

typeclassplay.scala

import simulacrum._

@typeclass trait CanTruthy[A] { self =>
  @op("!!") def truthy(a: A): Boolean
}

object Main extends App {
  import CanTruthy.ops._

  implicit val truthyInt =
    new CanTruthy[Int] {
      def truthy(a: Int) = a != 0
    }

  implicit val truthyString =
    new CanTruthy[String] {
      def truthy(a: String) = a != ""
    }

  println(5 !!)
  println("hello" !!)
}