bug: default impl trait bound on associated type not found

[MagisterDallis]

Bug Report

Cairo version:
6837d54

Current behavior:

    fn next(ref self: T) -> Option<Self::Item>;

    fn advance_by<+Destruct<T>, +Destruct<Self::Item>>(
        ref self: T, n: usize,
    ) -> Result<
        (), NonZero<usize>,
    > {
        let mut n = n;
        let mut res = Result::Ok(());
        while let Option::Some(nz_n) = n.try_into() {
            if let Option::Some(_) = Self::next(ref self) {
                n -= 1;
            } else {
                res = Result::Err(nz_n);
                break;
            }
        };
        res
    }
}

Implementing this should work in theory, but in practice, the following test fails to compile because:

#[test]
fn test_advance_by() {
    let mut iter = array![1_u8, 2, 3, 4].into_iter();

    assert_eq!(iter.advance_by(2), Result::Ok(()));
    assert_eq!(iter.next(), Option::Some(3));
    assert_eq!(iter.advance_by(0), Result::Ok(()));
    assert_eq!(iter.advance_by(100), Result::Err(99));
}

error: Trait has no implementation in context: core::traits::Destruct::<Iterator::Item>.
 --> corelib/src/test/iter_test.cairo:5:21
    assert_eq!(iter.advance_by(2), Result::Ok(()));