Support Soa vector to be Sync, Send

[PPakalns]

Useful when Soa is accessed from multiple threads.

Maybe this could be implemented in more safe way.

[tim-harding]

I agree that Soa should be Send and Sync where possible. It was at one point, but it looks like I forgot to add it back during a big safety refactor. However, I would choose to add it back to Slice, which Soa will inherit, and condition it on T's traits rather than the traits of its fields. I don't think SoaRaw is an appropriate place to implement these traits for the same reasons that raw pointers shouldn't implement them. Just because an f32 is shareable across threads doesn't mean that *mut f32 is, unless there is a safe interface around it. Since Soa and Slice semantically contain values of T, we should also respect manual trait impls or negative impls for that type. A two-liner in slice.rs should do the trick if you want the contribution.

[PPakalns]

I agree that Soa should be Send and Sync where possible. It was at one point, but it looks like I forgot to add it back during a big safety refactor. However, I would choose to add it back to Slice, which Soa will inherit, and condition it on T's traits rather than the traits of its fields. I don't think SoaRaw is an appropriate place to implement these traits for the same reasons that raw pointers shouldn't implement them. Just because an f32 is shareable across threads doesn't mean that *mut f32 is, unless there is a safe interface around it. Since Soa and Slice semantically contain values of T, we should also respect manual trait impls or negative impls for that type. A two-liner in slice.rs should do the trick if you want the contribution.

Good observation, needed to get it with Sync and Send and just implemented Sync and Send for type that compiler mentioned.

Implemented your suggestion.

[tim-harding]

Looks good to me!