As far as I know Rust doesn't have a memory model fully defined yet, but their type system already helps a lot.

https://github.com/nikomatsakis/rust-memory-model

A bit old, https://blog.rust-lang.org/2015/04/10/Fearless-Concurrency.h...

We don't, but there's been a ton of work; http://plv.mpi-sws.org/rustbelt/

For this kind of thing we mostly say "we defer to the C++ memory model" at the moment.