Struct UniformU64Sampler 

pub struct UniformU64Sampler { /* private fields */ }

Compatibility uniform range [0, limit) sampler for u64 numbers

Sampler uses provided rand::Rng reference to generate random u64 numbers and map them to desired range maintaining uniform distribution of generated numbers.

This utility exists only to provide compatibility of sampling algorithm with rand library at versions <=0.8.5, since parts of the system rely on reproducible sequence of numbers given stable seeded random number generator.

Two sampling algorithms are supported (they initialize internal zone value in different ways) to provide compatibility with two ways rand sampling can be performed:

• new_like_instance_sample: reproduces values obtained from sampler instance created with rand::distributions::uniform::UniformSampler::new and then used by calling sample
• new_like_trait_sample: reproduces values obtained from trait function calls rand::distributions::uniform::UniformSampler::sample_single

Implementations

impl UniformU64Sampler

pub fn new_like_instance_sample(range_end: NonZero<u64>) -> Self

Create sampler reproducing sample calls on UniformInt instance

The zone internal threshold is obtained by calculating modulo of u64::MAX’s difference with provided range’s end to itself. See: https://github.com/rust-random/rand/blob/937320cbfeebd4352a23086d9c6e68f067f74644/src/distributions/uniform.rs#L458-L504

pub fn new_like_trait_sample(range_end: NonZero<u64>) -> Self

Create sampler reproducing direct sample_single calls on UniformInt trait

The zone internal threshold is obtained by calculating 2^{number of leading zeros in provided range}. See https://github.com/rust-random/rand/blob/937320cbfeebd4352a23086d9c6e68f067f74644/src/distributions/uniform.rs#L534-L553

pub fn sample(&self, rng: &mut impl Rng) -> u64

Obtain random number from rng and map it to the initialized range of this sampler

Trait Implementations

impl Debug for UniformU64Sampler

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

Formats the value using the given formatter.