`struct DisjointMut`: `unsafe impl Send + Sync`

[kkysen]

Does this reasoning make sense?

In particular, I'm unsure about the provenanceless thing and data races not leading to memory unsafety. Is this worth it to say? Is it worth it to add an unsafe trait Provenanceless to ensure such a thing at a more detailed level? I do think it's an important point that data races won't lead to memory unsafety, though.

[kkysen]

Do we need the T: Send + Sync bounds in the unsafe impl Send + Sync here? Because as is, Rav1dPictureDataComponent is not Send or Sync (which we need it to be) since it contains a ptr: NonNull<u8>. This ptr is not Sync, however, as no synchronization is done.

[rinon]

I think we need to require it. If that pointer is indeed safe to share we need to mark it as such.

[kkysen]

I think we need to require it. If that pointer is indeed safe to share we need to mark it as such.

It's not safe, though. That's the problem.

[kkysen]

Let me think about it some more.