Module rand

Utilities for random number generation.

The implementation uses wyrand for now. It’s NOT cryptographically secure.

Examples

The public functions in rand is NOT reproducible due to possible replacement in future library versions.

For a reproducible generator, use a named PRNG struct, e.g. WyRng.

Generate a random u64:

let r = fstd::rand::u64(..);

Generate a random u64 in the [0,100):

let r = fstd::rand::u64(0..100);

Create a local PRNG with a random seed and generate a random u64:

use fstd::rand::WyRng;
let rng = WyRng::new();
let r = rng.u64(..);

Create a local PRNG with specific seed and generate a random u64, it is a reproducible generator.

use fstd::rand::WyRng;
let rng = WyRng::from_seed_u64(123);
let r = rng.u64(..);

Structs

WyRng

A random number generator based on wyrand. It’s NOT cryptographically secure.

Functions

f32

Returns a random f32 in the [0.0,1.0). (thread-safe, but not cryptographically secure)

f64

Returns a random f64 in the [0.0,1.0). (thread-safe, but not cryptographically secure)

i32

Returns a random i32 in the given range(thread-safe, but not cryptographically secure). Panics if the range is invalid.

i64

Returns a random i64 in the given range(thread-safe, but not cryptographically secure). Panics if the range is invalid.

isize

Returns a random isize in the given range(thread-safe, but not cryptographically secure). Panics if the range is invalid.

u32

Returns a random u32 in the given range(thread-safe, but not cryptographically secure). Panics if the range is invalid.

u64

Returns a random u64 in the given range(thread-safe, but not cryptographically secure). Panics if the range is invalid.

usize

Returns a random usize in the given range(thread-safe, but not cryptographically secure). Panics if the range is invalid.