Selection Sort In Scala

selectionsort.scala

/*
While refreshing how to determine orders of algorithms: O, Ω, atc. using an online tutorial, it covered selecton sort as an 
example.  So, I decided to implment it in Scala to be a generic version, sort of.
*/
import Ordering.Implicits._

def indexOfMinimum[T:Ordering](a: Array[T], start: Int) : Int = {
  var minValue = a(start)
  var mindex = start

  for( i <- mindex+1 until a.length) {
    if (a(i) < minValue) {
      minValue = a(i)
      mindex = i
    }
  }

  return mindex
}

def swap[T](a: Array[T], to: Int, from: Int) : Unit = {
  val temp = a(to)
  a(to) = a(from)
  a(from) = temp
}

def selectionSort[T:Ordering](a: Array[T]) : Unit = {
  for (i <- 0 until a.length) {
    val mindex = indexOfMinimum(a, i)
    swap(a, i, mindex)
  }