v/vlib/v/checker/tests/is_type_invalid.vv

type IoS = int | string

interface Animal {
	speak()
}

struct Dog {}

fn (d Dog) speak() {}

struct Cat {}

fn main() {
	if IoS(1) is u8 {
		println('not cool')
	}
	a := Animal(Dog{})
	if a is Cat {
		println('not cool either')
	}
}