sortedSetOf

Returns a new java.util.SortedSet with the given elements.

fun <T> sortedSetOf(vararg elements: T): TreeSet<T>(source)
val numbers = sortedSetOf(5, 3, 8, 1, 4)

for (n in numbers) {
    println(n)   // prints: 1 3 4 5 8
}

Source