Consider adding BytesRef

[carllerche]

This would be the Bytes equivalent of WakerRef.

If we do that, then we could switch Bytes::slice_ref -> BytesRef::new(&my_bytes, my_slice)... possibly even adding BytesRef::new_unchecked.

Follow up to #298.

[seanmonstar]

What does this add over let slice = &bytes[a..b]?

[carllerche]

It lets you slice further into owned handles.

[Matthias247]

When you clone a WakerRef you get a Waker. Which in Wakers cases typically is just a refcount bump, since the Waker has already been allocated.

What would cloneing a BytesRef do? If it gives us Bytes, then the clone in the vtable needs to be implemented as a heap allocation. If it gives us another BytesRef (in order to just slice the ref), then the required vtable function is different.