Crate rand 

Utilities for random number generation

Rand provides utilities to generate random numbers, to convert them to useful types and distributions, and some randomness-related algorithms.

Quick Start

// The prelude import enables methods we use below, specifically
// Rng::random, Rng::sample, SliceRandom::shuffle and IndexedRandom::choose.
use rand::prelude::*;

// Get an RNG:
let mut rng = rand::rng();

// Try printing a random unicode code point (probably a bad idea)!
println!("char: '{}'", rng.random::<char>());
// Try printing a random alphanumeric value instead!
println!("alpha: '{}'", rng.sample(rand::distr::Alphanumeric) as char);

// Generate and shuffle a sequence:
let mut nums: Vec<i32> = (1..100).collect();
nums.shuffle(&mut rng);
// And take a random pick (yes, we didn't need to shuffle first!):
let _ = nums.choose(&mut rng);

The Book

For the user guide and further documentation, please read The Rust Rand Book.

Re-exports

pub use rand_core;

Modules

distr

Generating random samples from probability distributions

prelude

Convenience re-export of common members

rngs

Random number generators and adapters

seq

Sequence-related functionality

Structs

RngReaderstd

Adapter to support std::io::Read over a TryRng

Traits

CryptoRng

A marker trait for securely unpredictable infallible RNGs

Fill

Support filling a slice with random data

Rng

Trait for infallible random number generators

RngExt

User-level interface for RNGs

SeedableRng

A random number generator that can be explicitly seeded.

TryCryptoRng

A marker trait over TryRng for securely unpredictable RNGs

TryRng

Base trait for random number generators and random data sources

Functions

fillthread_rng

Fill any type implementing Fill with random data

make_rngsys_rng

Construct and seed an RNG

randomthread_rng

Generate a random value using the thread-local random number generator.

random_boolthread_rng

Return a bool with a probability p of being true.

random_iterthread_rng

Return an iterator over random() variates

random_rangethread_rng

Generate a random value in the given range using the thread-local random number generator.

random_ratiothread_rng

Return a bool with a probability of numerator/denominator of being true.

rngthread_rng

Access a fast, pre-initialized generator