Struct Rng 

pub struct Rng { /* private fields */ }

A seeded stream of numbers, reproducible everywhere.

Implementations

impl Rng

pub const fn new(seed: u64) -> Rng

A stream from a seed.

pub const fn state(&self) -> u64

The seed a stream would need to be at this point again.

Every trial takes one of these and prints it on failure, so a hundred thousand trial run that fails on trial 74,113 hands back a number that reproduces trial 74,113 on its own in a millisecond.

pub const fn next_u64(&mut self) -> u64

The next number.

pub const fn below(&mut self, n: usize) -> usize

A number below n, or 0 when n is 0.

Biased, by about one part in 2^64 divided by n. Everything this picks is smaller than a few thousand, so the bias is not measurable and a rejection loop would only add a way for the harness to hang.

pub const fn between(&mut self, lo: usize, hi: usize) -> usize

A number in lo..=hi.

pub const fn chance(&mut self, num: u32, den: u32) -> bool

True with probability num in den.

Trait Implementations

impl Clone for Rng

fn clone(&self) -> Rng

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Rng

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

Formats the value using the given formatter.