Convert an array to a mutable set in Scala?

scala> val s=scala.collection.mutable.Set()++Array(1,2,3)
s: scala.collection.mutable.Set[Int] = Set(2, 1, 3)

scala> scala.collection.mutable.Set( Array(1,2) :_* )
res2: scala.collection.mutable.Set[Int] = Set(2, 1)

The weird :_* type ascription, forces factory method to see the array as a list of arguments.