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')
	}
}