fn foo<T: Deref<Target = [u32; {
    #[no_mangle]
    static FOO: usize = 42;
    3
}]>>(_: T) -> std::fmt::Debug {
    (42, PhantomData<T>)
}


existential type Foo<T>: std::fmt::Debug;

fn foo_desugared<T: Deref<Target = [u32; {
    #[no_mangle]
    static FOO: usize = 42;
    3
}]>>(_: T) -> Foo<T> {
    (42, PhantomData<T>)
}


fn main() {
    let mut x = foo();
    x = bar();
}