[RFC 2/2] rust: sync: Add atomic support

[Miguel Ojeda]

On Thu, Jun 13, 2024 at 9:05 PM Boqun Feng <boqun.feng at gmail.com> wrote:
>
> Does this make sense?

Implementation-wise, if you think it is simpler or more clear/elegant
to have the extra lower level layer, then that sounds fine.

However, I was mainly talking about what we would eventually expose to
users, i.e. do we want to provide `Atomic<T>` to begin with? If yes,
then we could make the lower layer private already.

We can defer that extra layer/work if needed even if we go for
`Atomic<T>`, but it would be nice to understand if we have consensus
for an eventual user-facing API, or if someone has any other opinion
or concerns on one vs. the other.

Cheers,
Miguel