struct Arrs {
mut:
    x [][]int
}

fn test_mut_array_index_option() {
    mut arr := Arrs{
        x: [[1, 2]]
    }
    for mut sub_arr in arr.x {
        x := sub_arr[0] or { 3 }
        println(x)
        assert x == 1
    }
}

fn test_array_index_option_with_if_expr() {
    ret := []string{}[0] or {
        if true { 'a' } else { 'b' }
    }
    println(ret)
    assert ret == 'a'
}