Struct MersenneTwister 

pub struct MersenneTwister {
    pub mt: [u32; 624],
    pub mti: usize,
}

Canonical MT19937 generator (N = 624, M = 397).

2496-byte state - kept behind alloc because RngBackend always boxes it.

Examples

use vrd::random::MersenneTwister;

let mut mt = MersenneTwister::new();
mt.seed(42);
let n = mt.rand();

Fields

mt: [u32; 624]

Internal MT19937 state vector - 624 32-bit words.

Examples

use vrd::random::MersenneTwister;

let mt = MersenneTwister::new();
assert_eq!(mt.mt.len(), 624);

mti: usize

Current index into Self::mt. Reaches 624 and triggers the next twist; an unseeded generator starts at 625.

Examples

use vrd::random::MersenneTwister;

let mut mt = MersenneTwister::new();
assert_eq!(mt.mti, 625); // unseeded sentinel
mt.seed(1);
assert_eq!(mt.mti, 624);

Implementations

impl MersenneTwister

pub fn new() -> Self

Creates a new generator with an empty state. Call Self::seed before use.

Examples

use vrd::random::MersenneTwister;

let mt = MersenneTwister::new();
assert_eq!(mt.mti(), 625);

pub fn from_seed(seed: [u8; 32]) -> Self

Seeds the generator from a 32-byte buffer; only the low 4 bytes are needed for MT19937 itself, but accepting 32 bytes keeps the API consistent with Xoshiro256PlusPlus::from_seed. The full 32 bytes are mixed via XOR-fold so callers don’t silently lose entropy.

Examples

use vrd::random::MersenneTwister;

let seed = [1u8; 32];
let mt = MersenneTwister::from_seed(seed);

pub fn seed(&mut self, seed: u32)

Seeds the MT state from a 32-bit value using the canonical Knuth multiplier constant.

Examples

use vrd::random::MersenneTwister;

let mut mt = MersenneTwister::new();
mt.seed(12345);

pub fn twist(&mut self)

Performs the MT twist on the state vector.

Examples

use vrd::random::MersenneTwister;

let mut mt = MersenneTwister::new();
mt.seed(42);
mt.twist();

pub fn rand(&mut self) -> u32

Generates the next u32.

Examples

use vrd::random::MersenneTwister;

let mut mt = MersenneTwister::new();
mt.seed(42);
let n = mt.rand();

pub fn next_u64(&mut self) -> u64

Generates the next u64 by combining two u32 outputs.

Examples

use vrd::random::MersenneTwister;

let mut mt = MersenneTwister::new();
mt.seed(42);
let n = mt.next_u64();

pub fn mti(&self) -> usize

Returns the current index into the state vector.

Examples

use vrd::random::MersenneTwister;

let mt = MersenneTwister::new();
assert_eq!(mt.mti(), 625);

pub fn set_mti(&mut self, value: usize)

Forces the index to value; mostly useful for round-trip tests.

Examples

use vrd::random::MersenneTwister;

let mut mt = MersenneTwister::new();
mt.set_mti(100);
assert_eq!(mt.mti(), 100);

Trait Implementations

impl Clone for MersenneTwister

fn clone(&self) -> MersenneTwister

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MersenneTwister

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

Formats the value using the given formatter.

impl Default for MersenneTwister

fn default() -> Self

Returns a new instance using Self::new.

impl<'de> Deserialize<'de> for MersenneTwister

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Hash for MersenneTwister

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for MersenneTwister

fn cmp(&self, other: &MersenneTwister) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for MersenneTwister

fn eq(&self, other: &MersenneTwister) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for MersenneTwister

fn partial_cmp(&self, other: &MersenneTwister) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl SeedableRng for MersenneTwister

type Seed = [u8; 32]

Seed type, which is restricted to types mutably-dereferenceable as u8 arrays (we recommend [u8; N] for some N).

fn from_seed(seed: Self::Seed) -> Self

Create a new PRNG using the given seed.

fn seed_from_u64(state: u64) -> Self

Create a new PRNG using a u64 seed.

fn from_rng<R>(rng: &mut R) -> Self

where R: Rng + ?Sized,

Create a new PRNG seeded from an infallible Rng.

fn try_from_rng<R>(rng: &mut R) -> Result<Self, <R as TryRng>::Error>

where R: TryRng + ?Sized,

Create a new PRNG seeded from a potentially fallible Rng.

fn fork(&mut self) -> Self

where Self: Rng,

Fork this PRNG

fn try_fork(&mut self) -> Result<Self, Self::Error>

where Self: TryRng,

Fork this PRNG

impl Serialize for MersenneTwister

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl TryRng for MersenneTwister

type Error = Infallible

The type returned in the event of a RNG error.

fn try_next_u32(&mut self) -> Result<u32, Self::Error>

Return the next random u32.

fn try_next_u64(&mut self) -> Result<u64, Self::Error>

Return the next random u64.

fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Self::Error>

Fill dst entirely with random data.

impl Eq for MersenneTwister

impl StructuralPartialEq for MersenneTwister