primebench.rs

#![feature(iterator_step_by)]
extern crate rayon;
use rayon::prelude::*;
use std::time::SystemTime;

fn is_prime(n: i64) -> bool {
    if n == 1 || (n > 2 && n % 2 == 0) {
        false
    } else {
        let mut rbool = true;
        let sroot: i64 = (n as f64).sqrt() as i64;
        for i in (3..sroot).step_by(2) {
            if n % i == 0 {
                rbool = false;
                break;
            }
        }

        rbool
    }
}

fn main() {
    let input: Vec<i64> = (0..=1000000).collect();
    let start = SystemTime::now();
    for _ in 0..100 {
        let output: Vec<bool> = input.par_iter().map(|n| is_prime(*n)).collect();
    }
    let since_the_epoch = SystemTime::now()
        .duration_since(start)
        .expect("Time went backwards");
    println!("{:?}", since_the_epoch);
}