Return adjacents from a given element of a matrix

fun adjacents(i: Int, j: Int) : List<Pair<Int, Int>> {
    val adjs = mutableListOf<Pair<Int, Int>>()
    if (i > 0) adjs.add(Pair(i-1, j))
    if (j > 0) adjs.add(Pair(i, j-1))
    if (i < 2) adjs.add(Pair(i+1, j))
    if (j < 2) adjs.add(Pair(i, j+1))
    return adjs
}
val matrix = arrayOf(intArrayOf(1, 2, 3), intArrayOf(4, 5, 6), intArrayOf(7, 8, 9))
adjacents(0, 0)