# rand_core - Rust
Random number generation traits
Keywords: rust, rustlang, rust-lang, rand_core

# Crate rand_core

source · [−]
Expand description

Random number generation traits

This crate is mainly of interest to crates publishing implementations of `RngCore`. Other users are encouraged to use the `rand` crate instead which re-exports the main traits and error types.

`RngCore` is the core trait implemented by algorithmic pseudo-random number generators and external random-number sources.

`SeedableRng` is an extension trait for construction from fixed seeds and other random number generators.

`Error` is provided for error-handling. It is safe to use in `no_std` environments.

The `impls` and `le` sub-modules include a few small functions to assist implementation of `RngCore`.

## Modules

block

The `BlockRngCore` trait and implementation helpers

impls

Helper functions for implementing `RngCore` functions.

le

Little-Endian utilities

## Structs

Error

Error type of random number generators

OsRng

A random number generator that retrieves randomness from the operating system.

## Traits

CryptoRng

A marker trait used to indicate that an `RngCore` or `BlockRngCore` implementation is supposed to be cryptographically secure.

RngCore

The core of a random number generator.

SeedableRng

A random number generator that can be explicitly seeded.