Surprised nobody here nor on the reddit thread caught this one: https://github.com/nahla-nee/wfqueue/blob/main/src/lib.rs#L3...

    unsafe impl<T, const N: usize> Sync for WFQueue<T, N> {}
    unsafe impl<T, const N: usize> Send for WFQueue<T, N> {}

These impls are unsound, because neither constrains `T` to be `Sync`/`Send`. As-written this would let you declare a `WFQueue<Rc<T>, N>` and pass non-atomic-refcount pointers between threads.

The fix is straightforward:

    unsafe impl<T: Sync, const N: usize> Sync for WFQueue<T, N> {}
    unsafe impl<T: Send, const N: usize> Send for WFQueue<T, N> {}

I.e., WFQueue is only Sync if T is Sync, and likewise for Send.

Actually, later on, the code makes a similar mistake, but only for one impl.

    unsafe impl<'a, T, const N: usize> Send for DrivableWFEnqueue<'a, T, N> where T: Send {}
    unsafe impl<'a, T, const N: usize> Send for DrivableWFDequeue<'a, T, N> {}