struct Foo {
mut:
    x int
}

struct Bar {
mut:
    y int
}

type Foobar = Foo | Bar

fn mutate_foobar1(mut foobar Foobar) {
    match foobar {
        Foo {
            mutate_foo(mut foobar)
        }
        Bar {
            mutate_bar(mut foobar)
        }
    }
}

fn mutate_foobar2(mut foobar Foobar) int {
    return match foobar {
        Foo {
            mutate_foo(mut foobar)
        }
        Bar {
            mutate_bar(mut foobar)
        }
    }
}

fn mutate_foo(mut foo Foo) int {
    foo.x = 5
    return 5
}

fn mutate_bar(mut bar Bar) int {
    bar.y = 10
    return 10
}

fn main() {
    mut bar := Bar{
        y: 0
    }
    mutate_foobar1(mut bar)
    mutate_foobar2(mut bar)
}