Struct rand::rngs::adapter::ReadRng

[+] Show declaration

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

[−] Expand description

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_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::{read, Rng};

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

Methods

impl<R: Read> ReadRng<R>

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

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Create a new ReadRng from a Read.

Trait Implementations

impl<R: Debug> Debug for ReadRng<R>

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

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Formats the value using the given formatter.

impl<R: Read> RngCore for ReadRng<R>

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fn next_u32(&mut self) -> u32

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Return the next random u32.

fn next_u64(&mut self) -> u64

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Return the next random u64.

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

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Fill dest with random data.

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

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Fill dest entirely with random data.