Struct rand::os::OsRng

pub struct OsRng(_);

A random number generator that retrieves randomness straight from the operating system. Platform sources:

• Unix-like systems (Linux, Android, Mac OSX): read directly from /dev/urandom, or from getrandom(2) system call if available.
• OpenBSD: calls getentropy(2)
• FreeBSD: uses the kern.arandom sysctl(2) mib
• Windows: calls RtlGenRandom, exported from advapi32.dll as SystemFunction036.
• iOS: calls SecRandomCopyBytes as /dev/(u)random is sandboxed.
• PNaCl: calls into the nacl-irt-random-0.1 IRT interface.

This usually does not block. On some systems (e.g. FreeBSD, OpenBSD, Max OS X, and modern Linux) this may block very early in the init process, if the CSPRNG has not been seeded yet.[1]

[1] See https://www.python.org/dev/peps/pep-0524/ for a more in-depth discussion.

Methods

impl OsRng

pub fn new() -> Result<OsRng>

Create a new OsRng.

Trait Implementations

impl Rng for OsRng

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, v: &mut [u8])

Fill dest with random data.

fn next_f32(&mut self) -> f32

Return the next random f32 selected from the half-open interval [0, 1).

fn next_f64(&mut self) -> f64

Return the next random f64 selected from the half-open interval [0, 1).

fn gen<T: Rand>(&mut self) -> T where
    Self: Sized, 

Return a random value of a Rand type.

Important traits for Generator<'a, T, R>

impl<'a, T: Rand, R: Rng> Iterator for Generator<'a, T, R> type Item = T;

fn gen_iter<'a, T: Rand>(&'a mut self) -> Generator<'a, T, Self> where
    Self: Sized, 

Return an iterator that will yield an infinite number of randomly generated items.

fn gen_range<T: PartialOrd + SampleRange>(&mut self, low: T, high: T) -> T where
    Self: Sized, 

Generate a random value in the range [low, high).

fn gen_weighted_bool(&mut self, n: u32) -> bool where
    Self: Sized, 

Return a bool with a 1 in n chance of true

Important traits for AsciiGenerator<'a, R>

impl<'a, R: Rng> Iterator for AsciiGenerator<'a, R> type Item = char;

fn gen_ascii_chars<'a>(&'a mut self) -> AsciiGenerator<'a, Self> where
    Self: Sized, 

Return an iterator of random characters from the set A-Z,a-z,0-9.

fn choose<'a, T>(&mut self, values: &'a [T]) -> Option<&'a T> where
    Self: Sized, 

Return a random element from values.

fn choose_mut<'a, T>(&mut self, values: &'a mut [T]) -> Option<&'a mut T> where
    Self: Sized, 

Return a mutable pointer to a random element from values.

fn shuffle<T>(&mut self, values: &mut [T]) where
    Self: Sized, 

Shuffle a mutable slice in place.

impl Debug for OsRng

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

Formats the value using the given formatter.