Determine number of cores using Rust

Question

I want to spawn a certain number of tasks based on the cores that a machine has. Is there anything in Rust that can find the number of cores, or should I just run external commands and parse the output?

Answer 1

There's now a crate to do this: https://crates.io/crates/num_cpus

Add this to your Cargo.toml:

[dependencies] num_cpus = "0.2" 

Then in your source:

extern crate num_cpus; let num = num_cpus::get(); 

Answer 2

You could use std::os::num_cpus. Example:

fn main() {     println!("{}", std::os::num_cpus()); }