gecko-dev/third_party/rust/rand

rand

A Rust library for random number generators and other randomness functionality.

Documentation

Usage

Add this to your Cargo.toml:

[dependencies]
rand = "0.3"

and this to your crate root:

extern crate rand;

Examples

There is built-in support for a random number generator (RNG) associated with each thread stored in thread-local storage. This RNG can be accessed via thread_rng, or used implicitly via random. This RNG is normally randomly seeded from an operating-system source of randomness, e.g. /dev/urandom on Unix systems, and will automatically reseed itself from this source after generating 32 KiB of random data.

let tuple = rand::random::<(f64, char)>();
println!("{:?}", tuple)

use rand::Rng;

let mut rng = rand::thread_rng();
if rng.gen() { // random bool
    println!("i32: {}, u32: {}", rng.gen::<i32>(), rng.gen::<u32>())
}

It is also possible to use other RNG types, which have a similar interface. The following uses the "ChaCha" algorithm instead of the default.

use rand::{Rng, ChaChaRng};

let mut rng = rand::ChaChaRng::new_unseeded();
println!("i32: {}, u32: {}", rng.gen::<i32>(), rng.gen::<u32>())