Struct rand_mt::Mt19937GenRand64
source · pub struct Mt19937GenRand64 { /* private fields */ }
Expand description
The 64-bit flavor of the Mersenne Twister pseudorandom number generator.
§Size
Mt19937GenRand64
requires approximately 2.5 kilobytes of internal state.
You may wish to store an Mt19937GenRand64
on the heap in a Box
to make it
easier to embed in another struct.
Mt19937GenRand64
is also the same size as
Mt19937GenRand32
.
assert_eq!(2504, mem::size_of::<Mt19937GenRand64>());
assert_eq!(mem::size_of::<Mt19937GenRand32>(), mem::size_of::<Mt19937GenRand64>());
Implementations§
source§impl Mt19937GenRand64
impl Mt19937GenRand64
sourcepub const DEFAULT_SEED: u64 = 5_489u64
pub const DEFAULT_SEED: u64 = 5_489u64
Default seed used by Mt19937GenRand64::new_unseeded
.
sourcepub fn new(seed: u64) -> Self
pub fn new(seed: u64) -> Self
Create a new Mersenne Twister random number generator using the given seed.
§Examples
§Constructing with a u64
seed
let seed = 123_456_789_u64;
let mt1 = Mt19937GenRand64::new(seed);
let mt2 = Mt19937GenRand64::from(seed.to_le_bytes());
assert_eq!(mt1, mt2);
§Constructing with default seed
let mt1 = Mt19937GenRand64::new(Mt19937GenRand64::DEFAULT_SEED);
let mt2 = Mt19937GenRand64::new_unseeded();
assert_eq!(mt1, mt2);
sourcepub fn new_with_key<I>(key: I) -> Self
pub fn new_with_key<I>(key: I) -> Self
Create a new Mersenne Twister random number generator using the given key.
Key can have any length.
sourcepub fn new_unseeded() -> Self
pub fn new_unseeded() -> Self
Create a new Mersenne Twister random number generator using the default fixed seed.
§Examples
// Default MT seed
let seed = 5489_u64;
let mt = Mt19937GenRand64::new(seed);
let unseeded = Mt19937GenRand64::new_unseeded();
assert_eq!(mt, unseeded);
sourcepub fn next_u64(&mut self) -> u64
pub fn next_u64(&mut self) -> u64
Generate next u64
output.
u64
is the native output of the generator. This function advances the
RNG step counter by one.
§Examples
let mut mt = Mt19937GenRand64::new_unseeded();
assert_ne!(mt.next_u64(), mt.next_u64());
sourcepub fn next_u32(&mut self) -> u32
pub fn next_u32(&mut self) -> u32
Generate next u32
output.
This function is implemented by generating one u64
from the RNG and
performing shifting and masking to turn it into a u32
output.
§Examples
let mut mt = Mt19937GenRand64::new_unseeded();
assert_ne!(mt.next_u32(), mt.next_u32());
sourcepub fn fill_bytes(&mut self, dest: &mut [u8])
pub fn fill_bytes(&mut self, dest: &mut [u8])
Fill a buffer with bytes generated from the RNG.
This method generates random u64
s (the native output unit of the RNG)
until dest
is filled.
This method may discard some output bits if dest.len()
is not a
multiple of 8.
§Examples
let mut mt = Mt19937GenRand64::new_unseeded();
let mut buf = [0; 32];
mt.fill_bytes(&mut buf);
assert_ne!([0; 32], buf);
let mut buf = [0; 31];
mt.fill_bytes(&mut buf);
assert_ne!([0; 31], buf);
sourcepub fn recover<I>(key: I) -> Result<Self, RecoverRngError>where
I: IntoIterator<Item = u64>,
pub fn recover<I>(key: I) -> Result<Self, RecoverRngError>where
I: IntoIterator<Item = u64>,
Attempt to recover the internal state of a Mersenne Twister using the past 312 samples.
This conversion takes a history of samples from a RNG and returns a RNG that will produce identical output to the RNG that supplied the samples.
This constructor is also available as a TryFrom
implementation for
&[u32]
.
§Errors
If key
has less than 312 elements, an error is returned because there
is not enough data to fully initialize the RNG.
If key
has more than 312 elements, an error is returned because the
recovered RNG will not produce identical output to the RNG that supplied
the samples.
sourcepub fn reseed(&mut self, seed: u64)
pub fn reseed(&mut self, seed: u64)
Reseed a Mersenne Twister from a single u64
.
§Examples
// Default MT seed
let mut mt = Mt19937GenRand64::new_unseeded();
let first = mt.next_u64();
mt.fill_bytes(&mut [0; 512]);
// Default MT seed
mt.reseed(5489_u64);
assert_eq!(first, mt.next_u64());
sourcepub fn reseed_with_key<I>(&mut self, key: I)
pub fn reseed_with_key<I>(&mut self, key: I)
Reseed a Mersenne Twister from am iterator of u64
s.
Key can have any length.
Trait Implementations§
source§impl Clone for Mt19937GenRand64
impl Clone for Mt19937GenRand64
source§fn clone(&self) -> Mt19937GenRand64
fn clone(&self) -> Mt19937GenRand64
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl Debug for Mt19937GenRand64
impl Debug for Mt19937GenRand64
source§impl Default for Mt19937GenRand64
impl Default for Mt19937GenRand64
source§fn default() -> Self
fn default() -> Self
Return a new Mt19937GenRand64
with the default seed.
Equivalent to calling Mt19937GenRand64::new_unseeded
.
source§impl From<u64> for Mt19937GenRand64
impl From<u64> for Mt19937GenRand64
source§fn from(seed: u64) -> Self
fn from(seed: u64) -> Self
Construct a Mersenne Twister RNG from a u64
seed.
This function is equivalent to new
.
§Examples
// Default MT seed
let seed = 5489_u64;
let mt1 = Mt19937GenRand64::from(seed);
let mt2 = Mt19937GenRand64::new(seed);
assert_eq!(mt1, mt2);
// Non-default MT seed
let seed = 9927_u64;
let mt1 = Mt19937GenRand64::from(seed);
let mt2 = Mt19937GenRand64::new(seed);
assert_eq!(mt1, mt2);
source§impl Hash for Mt19937GenRand64
impl Hash for Mt19937GenRand64
source§impl Ord for Mt19937GenRand64
impl Ord for Mt19937GenRand64
source§fn cmp(&self, other: &Mt19937GenRand64) -> Ordering
fn cmp(&self, other: &Mt19937GenRand64) -> Ordering
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
source§impl PartialEq for Mt19937GenRand64
impl PartialEq for Mt19937GenRand64
source§fn eq(&self, other: &Mt19937GenRand64) -> bool
fn eq(&self, other: &Mt19937GenRand64) -> bool
self
and other
values to be equal, and is used
by ==
.source§impl PartialOrd for Mt19937GenRand64
impl PartialOrd for Mt19937GenRand64
source§fn partial_cmp(&self, other: &Mt19937GenRand64) -> Option<Ordering>
fn partial_cmp(&self, other: &Mt19937GenRand64) -> Option<Ordering>
1.0.0 · source§fn le(&self, other: &Rhs) -> bool
fn le(&self, other: &Rhs) -> bool
self
and other
) and is used by the <=
operator. Read moresource§impl RngCore for Mt19937GenRand64
impl RngCore for Mt19937GenRand64
source§fn next_u64(&mut self) -> u64
fn next_u64(&mut self) -> u64
Generate next u64
output.
u64
is the native output of the generator. This function advances the
RNG step counter by one.
§Examples
use rand_core::RngCore;
use rand_mt::Mt19937GenRand64;
let mut rng = Mt19937GenRand64::new_unseeded();
assert_ne!(rng.next_u64(), rng.next_u64());
source§fn next_u32(&mut self) -> u32
fn next_u32(&mut self) -> u32
Generate next u32
output.
This function is implemented by generating one u64
from the RNG and
performing shifting and masking to turn it into a u32
output.
§Examples
use rand_core::RngCore;
use rand_mt::Mt19937GenRand64;
let mut rng = Mt19937GenRand64::new_unseeded();
assert_ne!(rng.next_u32(), rng.next_u32());
source§fn fill_bytes(&mut self, dest: &mut [u8])
fn fill_bytes(&mut self, dest: &mut [u8])
Fill a buffer with bytes generated from the RNG.
This method generates random u64
s (the native output unit of the RNG)
until dest
is filled.
This method may discard some output bits if dest.len()
is not a
multiple of 8.
§Examples
use rand_core::RngCore;
use rand_mt::Mt19937GenRand64;
let mut rng = Mt19937GenRand64::new_unseeded();
let mut buf = [0; 32];
rng.fill_bytes(&mut buf);
assert_ne!([0; 32], buf);
let mut buf = [0; 31];
rng.fill_bytes(&mut buf);
assert_ne!([0; 31], buf);
source§fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error>
fn try_fill_bytes(&mut self, dest: &mut [u8]) -> Result<(), Error>
Fill a buffer with bytes generated from the RNG.
This method generates random u64
s (the native output unit of the RNG)
until dest
is filled.
This method may discard some output bits if dest.len()
is not a
multiple of 8.
try_fill_bytes
is implemented with fill_bytes
and is infallible.
§Examples
use rand_core::RngCore;
use rand_mt::Mt19937GenRand64;
let mut rng = Mt19937GenRand64::new_unseeded();
let mut buf = [0; 32];
rng.try_fill_bytes(&mut buf)?;
assert_ne!([0; 32], buf);
let mut buf = [0; 31];
rng.try_fill_bytes(&mut buf)?;
assert_ne!([0; 31], buf);
source§impl SeedableRng for Mt19937GenRand64
impl SeedableRng for Mt19937GenRand64
source§fn from_seed(seed: Self::Seed) -> Self
fn from_seed(seed: Self::Seed) -> Self
Reseed from a little endian encoded u64
.
§Examples
// Default MT seed
let seed = 5489_u64.to_le_bytes();
let mut mt = Mt19937GenRand64::from_seed(seed);
assert_ne!(mt.next_u64(), mt.next_u64());
§type Seed = [u8; 8]
type Seed = [u8; 8]
u8
arrays (we recommend [u8; N]
for some N
). Read moresource§fn seed_from_u64(state: u64) -> Self
fn seed_from_u64(state: u64) -> Self
u64
seed. Read moresource§impl TryFrom<&[u64]> for Mt19937GenRand64
impl TryFrom<&[u64]> for Mt19937GenRand64
source§fn try_from(key: &[u64]) -> Result<Self, Self::Error>
fn try_from(key: &[u64]) -> Result<Self, Self::Error>
Attempt to recover the internal state of a Mersenne Twister using the past 312 samples.
This conversion takes a history of samples from a RNG and returns a RNG that will produce identical output to the RNG that supplied the samples.
This conversion is implemented with Mt19937GenRand64::recover
.
§Errors
If key
has less than 312 elements, an error is returned because there
is not enough data to fully initialize the RNG.
If key
has more than 312 elements, an error is returned because the
recovered RNG will not produce identical output to the RNG that supplied
the samples.