struct Foo;

struct FooFilter<'a> {
    foo: &'a Foo,
}

trait Filter<'a> {
    type Output;

    fn make_filter(&'a mut self) -> Self::Output;
}

impl<'a> Filter<'a> for Foo {
    type Output = FooFilter<'a>;

    fn make_filter(&'a mut self) -> Self::Output {
        FooFilter { foo: &*self }
    }
}

pub trait Scan<Filter> {}

impl<'a> Scan<FooFilter<'a>> for Foo {}

trait Assert1<'a>
where
    Self: Filter<'a>,
    Self: Scan<<Self as Filter<'a>>::Output>,
{
}
impl<'a> Assert1<'a> for Foo {}

trait Assert2
where
    for<'a> Self: Filter<'a>,
    Self: for<'a> Scan<<Self as Filter<'a>>::Output>,
{
}
impl Assert2 for Foo {}

fn main() {}