| // run-pass |
| #![allow(unused_imports)] |
| use std::thread; |
| use std::sync::Mutex; |
| |
| fn par_for<I, F>(iter: I, f: F) |
| where I: Iterator, |
| I::Item: Send, |
| F: Fn(I::Item) + Sync |
| { |
| for item in iter { |
| f(item) |
| } |
| } |
| |
| fn sum(x: &[i32]) { |
| let sum_lengths = Mutex::new(0); |
| par_for(x.windows(4), |x| { |
| *sum_lengths.lock().unwrap() += x.len() |
| }); |
| |
| assert_eq!(*sum_lengths.lock().unwrap(), (x.len() - 3) * 4); |
| } |
| |
| fn main() { |
| let mut elements = [0; 20]; |
| |
| // iterators over references into this stack frame |
| par_for(elements.iter_mut().enumerate(), |(i, x)| { |
| *x = i as i32 |
| }); |
| |
| sum(&elements) |
| } |