[jzoch]

> They could not actually do this in Rust. They had to cheat.

That isn't true at all. The implementation of scoped_threadpool being in rust is all the evidence you need that they did not cheat. unsafe is a perfectly valid construct in rust that does not subvert its benefits. It just is a reversal of the defaults in other languages (unsafe by default - opt-in to safer constructs like smart_ptr).

People freak out too much over this stuff. If you are learning - feel free to use escape hatches from "idiomatic rust" but recognize that you aren't being idiomatic (and therefore may be handicapping your learning!). Its okay to use unsafe despite idiomatic rust trying to avoid it unless necessary (and even then providing safe wrappers over it). Its also okay to use Arc<Mutex> and the like if you need to just recognize there may be a better way.