Struct rand::rngs::adapter::ReadRng

pub struct ReadRng<R> { /* fields omitted */ }

An RNG that reads random bytes straight from any type supporting [std::io::Read], for example files.

This will work best with an infinite reader, but that is not required.

This can be used with /dev/urandom on Unix but it is recommended to use OsRng instead.

Panics

ReadRng uses [std::io::Read::read_exact], which retries on interrupts. All other errors from the underlying reader, including when it does not have enough data, will only be reported through try_fill_bytes. The other [RngCore] methods will panic in case of an error.

Example

use rand::Rng;
use rand::rngs::adapter::ReadRng;

let data = vec![1, 2, 3, 4, 5, 6, 7, 8];
let mut rng = ReadRng::new(&data[..]);
println!("{:x}", rng.gen::<u32>());

Methods

impl<R: Read> ReadRng<R>

pub fn new(r: R) -> ReadRng<R>

Create a new ReadRng from a Read.

Trait Implementations

impl<R: Debug> Debug for ReadRng<R>

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<R: Read> RngCore for ReadRng<R>

fn next_u32(&mut self) -> u32

Return the next random u32.

fn next_u64(&mut self) -> u64

Return the next random u64.

fn fill_bytes(&mut self, dest: &mut [u8])

Fill dest with random data.

fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error>

Fill dest entirely with random data.