I do not see that concurrency is a first class concept in Rust at all. The only mechanism that is in the language are the Send and Sync traits, and is even part

I do not see that concurrency is a first class concept in Rust at all. The only mechanism that is in the language are the Send and Sync traits, and is even partially out of it. Rust do not have language constructs for any concurrency/parallel model, and this is a good thing. You can use fork-join, parallel iterators, mutex, rwlocks, channels (mpsc, mpmc...) or any other model as a library. The nice thing is that, as you say, is the type system the component that guarantee a free from data race code in safe Rust.