struct Container[T] {
mut:
    items []T
}

fn (mut c Container[T]) pop() ?T {
    return c.items.pop()
}

struct Item {
    data     string
    priority int
}

fn test_generic_array_pop_call() {
    mut a1 := Container[int]{
        items: [11, 22]
    }
    println(a1)
    ret1 := a1.pop() or { 0 }
    println(ret1)
    assert ret1 == 22

    item1 := Item{'a', 1}
    item2 := Item{'b', 2}
    mut a2 := Container[Item]{
        items: [item1, item2]
    }
    println(a2)
    ret2 := a2.pop() or { Item{} }
    assert ret2 == item2
}