alt Hacker NewsThis has the same drawbacks as "#pragma omp for".
The hard part isn't splitting loop iterations between threads, but doing so _safely_.
Proving an arbitrary loop's iterations are split in a memory safe way is an NP hard problem in C and C++, but the default behavior in Rust.
Replies
pjmlp • today at 6:43 AM
Well, if you are accessing global data with ranges, you are doing it wrong.
Naturally nothing on C++ prevents someone to do that, which is why PVS, Sonar and co exist.
Just like some things aren't prevented by Rust rather clippy.
Concurrency is easy by default. The hard part is when you are trying to be clever.
You write concurrent code in Rust pretty much in the same way as you would write it in OpenMP, but with some extra syntax. Rust catches some mistakes automatically, but it also forces you to do some extra work. For example, you often have to wrap shared data in Arc when you convert single-threaded code to use multiple threads. And some common patterns are not easily available due to the limited ownership model. For example, you can't get mutable references to items in a shared container by thread id or loop iteration.