rapidrand

An extremely fast pseudo-random number generator, using the rapidhash mixing algorithm, designed for the rand crate and based on wyrand.

• Extremely fast: matching the performance of fastrand, nanorand, and turborand that all use the same PRNG construction but their own RNG traits.
• High quality: passes TestU01's BigCrush and PractRand up to 16TB.
• Designed for rand: use the rand crate traits 10x faster. Perfect for testing, benchmarks, and synthetic datasets.
• Non-cryptographic: This is not a cryptographic random number generator.

Usage

RapidRng is built for the rand crate. Add both crates and use the full rand API:

[dependencies]
rand = "0.10"
rapidrand = "0.1"

Seed it from rand's thread-local RNG (itself seeded from the OS) with from_rng:

use rand::{RngExt, SeedableRng, rng};   // RngExt brings `.random()`, `.random_range()`, ...
use rapidrand::RapidRng;

let mut rapid = RapidRng::from_rng(&mut rng());

let coin: bool = rapid.random();
let roll = rapid.random_range(1..=6);
let x: u32 = rapid.random();

For a reproducible stream, seed it from a fixed value instead:

use rand::{RngExt, SeedableRng};
use rapidrand::RapidRng;

let mut rapid = RapidRng::seed_from_u64(42);
let x: u32 = rapid.random();

Without the rand crate

RapidRng also works with just rand_core's traits, using next_u64 for a u64:

use rapidrand::RapidRng;
use rand_core::{Rng, SeedableRng};

let mut rng = RapidRng::seed_from_u64(42);
let x = rng.next_u64();

Or use the standalone function directly, threading the seed yourself:

use rapidrand::rapidrng;

let mut state: u64 = 42;
let x = rapidrng(&mut state);

Features

• Default: rand
• rand: implements rand_core's Rng / SeedableRng and enables RapidRng (rand 0.10).

License

Licensed under either of Apache-2.0 or MIT at your option.