euros

euros.scala

object Euros {
  trait Currency

  case class Euro(int: Int) extends AnyVal with Currency {
    def +(m: Euro): Euro = new Euro(int + m.int)
  }

  implicit class EuroToInt(int: Int) {
    def `€` = {
      Euro(int)
    }
  }
}

object CurrencyApp extends App {
  import Euros._

  val cagnotte: Euro = 0 `€`

  println(cagnotte + (1 `€`))
}