Struct rand::StdRng

pub struct StdRng { /* fields omitted */ }

The standard RNG. This is designed to be efficient on the current platform.

Methods

impl StdRng

pub fn new() -> Result<StdRng>

Create a randomly seeded instance of StdRng.

This is a very expensive operation as it has to read randomness from the operating system and use this in an expensive seeding operation. If one is only generating a small number of random numbers, or doesn't need the utmost speed for generating each number, thread_rng and/or random may be more appropriate.

Reading the randomness from the OS may fail, and any error is propagated via the io::Result return value.

Trait Implementations

impl Rng for StdRng

fn next_u32(&mut self) -> u32

Return the next random u32.

fn next_u64(&mut self) -> u64

Return the next random u64.

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

Fill dest with random data.

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<'a> SeedableRng<&'a [usize]> for StdRng

fn reseed(&mut self, seed: &'a [usize])

Reseed an RNG with the given seed.

fn from_seed(seed: &'a [usize]) -> StdRng

Create a new RNG with the given seed.

impl Clone for StdRng

fn clone(&self) -> StdRng

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for StdRng

impl Debug for StdRng

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

Formats the value using the given formatter.