Expand description
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.
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
Traits§
- Crypto
Rng - A marker trait over
RngCore
for securely unpredictable RNGs - Fill
- Types which may be filled with random data
- Rng
- User-level interface for RNGs
- RngCore
- Implementation-level interface for RNGs
- Seedable
Rng - A random number generator that can be explicitly seeded.
- TryCrypto
Rng - A marker trait over
TryRngCore
for securely unpredictable RNGs - TryRng
Core - A potentially fallible variant of
RngCore
Functions§
- fill
- Fill any type implementing
Fill
with random data - random
- Generate a random value using the thread-local random number generator.
- random_
bool - Return a bool with a probability
p
of being true. - random_
iter - Return an iterator over
random()
variates - random_
range - Generate a random value in the given range using the thread-local random number generator.
- random_
ratio - Return a bool with a probability of
numerator/denominator
of being true. - rng
- Access a fast, pre-initialized generator
- thread_
rng Deprecated - Access the thread-local generator