Struct Rng 

pub struct Rng { /* private fields */ }

Deterministic xorshift64* pseudo-random number generator.

Same seed always yields the same sequence across runs and platforms.

Not cryptographically secure: the full state is recoverable from the output, so never use it for security-sensitive values (tokens, secrets, nonces). It is meant for gameplay - procedural generation, spawn jitter, AI variation - where reproducibility matters and predictability does not.

Implementations

impl Rng

pub const DEFAULT_SEED: u64 = 0x4d59_5df4_d0f3_3173

Fallback state used when a zero seed is supplied.

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

Creates a new deterministic generator from seed.

pub const fn reseed(&mut self, seed: u64)

Reseeds the generator. A zero seed falls back to Self::DEFAULT_SEED.

pub fn next_u64(&mut self) -> u64

Returns the next u64.

pub fn next_u32(&mut self) -> u32

Returns the next u32.

pub fn range_u32(&mut self, range: Range<u32>) -> u32

Returns a uniform u32 sampled from the half-open range.

Panics

Panics if range is empty (range.start >= range.end).

pub fn range_usize(&mut self, range: Range<usize>) -> usize

Returns a uniform usize sampled from the half-open range.

Panics

Panics if range is empty (range.start >= range.end).

pub fn next_f32(&mut self) -> f32

Returns a uniform f32 in [0, 1).

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<(), Error>

Formats the value using the given formatter.

impl Default for Rng

fn default() -> Rng

Seeds from Rng::DEFAULT_SEED.