struct Foo1 {}

struct Foo2 {}

type Foo = Foo1 | Foo2

fn main() {
	a := [1, 2, 3]
	if 4 !in a {
		println('4 not in a')
	}

	foo := Foo(Foo1{})
	if foo !is Foo2 {
		println('foo is not Foo2')
	}
}