Threading

rayon is a Rust library for parallelizing work. It uses the typesystem to provide a safe API.

#![allow(unused_imports)]

extern crate rayon;

use std::sync::atomic::{AtomicI32, Ordering};
use std::iter::FromIterator;
use rayon::prelude::*;

fn main() {
    // Create a list of integers from 0 to 100
    let range = Vec::from_iter(0..100);

    let mut total = 0;

    range.iter().for_each(|&n| {
        total += n;
    });

    println!("{}", total);
}

Note the difference in the signatures of the two for_each methods

• Iterator::for_each
• ParallelIterator::method.for_each

Fn and FnMut are traits describing closures. FnMut closures need mutable access to their environment, whereas Fn closures only need shared access and so are safe to run concurrently.