trait Foo<Input> {
    type Output;
}

trait Bar {
    type Input;

    fn baz<F: Foo<Self::Input>>() -> F::Output
    where
        F::Output: Default;
}

impl<T> Bar for T {
    type Input = T;

    fn baz<F: Foo<Self::Input>>() -> F::Output
    where
        F::Output: Default,
    {
    }
}