Example2.scala

//we have our monoid
trait Monoid[T] {
    def associative(t1:T,t2:T):T
    def zero:T
  }

// lets have an implimentaion for int type
implicit val IntSumMonoid = new Monoid[Int] {
  def associative(t1:Int,t2:Int): t1 + t2
  def zero:Int = 0
}

//here is how our function will look now
def summ[T](xs:List[T])(implicit val m:Monoid[T]):T = xs.foldLeft(m.zero)(m.associative)

//this is how we can call our polymorphic function
//no need to pass the second parameter as its implicit
summ(List(1,2,3,4))