Generic Fill. Works with arrays too.

gistfile1.scala

scala>  def fill[A, CC[_]](n: Int)(elem: => A)(implicit cbf:
     |    CanBuildFrom[Nothing, A, CC[A]]) = {
     |    val b = cbf()
     |    for(_ <- 1 to n)
     |      b += elem
     |    b.result
     | }
fill: [A, CC[_]](n: Int)(elem: => A)(implicit cbf: scala.collection.generic.CanB
uildFrom[Nothing,A,CC[A]])CC[A]

scala> fill[Int, List](5)(4)
res46: List[Int] = List(4, 4, 4, 4, 4)

scala> fill[Int, Array](5)(4)
res47: Array[Int] = Array(4, 4, 4, 4, 4)