ImplicitPimpMyLibrary.scala

   //Implicit Ordering

    case class SalesClass(product:String, unitPrice:Double, qty:Int){
      def totalPrice :Double = unitPrice * qty
    }



    object ProductSorting {
      // Note that because `Ordering[A]` is not contravariant, the declaration
      // must be type-parametrized in the event that you want the implicit
      // ordering to apply to subclasses of `SalesClass`.
      implicit def classStringSorting[A <:SalesClass]: Ordering[A] = {
        Ordering.fromLessThan((a, b) => a.product.compareTo(b.product) < 0)
      }
    }

    object TotalSort {
      implicit def totalPriceOrdering: Ordering[SalesClass] = {
        Ordering.fromLessThan((a, b) => a.totalPrice < b.totalPrice)
      }
    }

    val sales:List[SalesClass]= List(
      SalesClass("Pear",2.5,10),
      SalesClass("Banana",0.5,10),
      SalesClass("Apple",1.5,10)
    )


    println(sales)
    sales.foreach(record => println(record.totalPrice)) // 5.0 15.0 , 25.0

    import ProductSorting._
    println(sales.sorted) // List(SalesClass(Apple,1.5,10), SalesClass(Banana,0.5,10), SalesClass(Pear,2.5,10))


    import TotalSort._
    println(sales.sorted)