# Struct rand_pcg::Lcg64Xsh32

source · `pub struct Lcg64Xsh32 { /* private fields */ }`

## Expand description

A PCG random number generator (XSH RR 64/32 (LCG) variant).

Permuted Congruential Generator with 64-bit state, internal Linear Congruential Generator, and 32-bit output via “xorshift high (bits), random rotation” output function.

This is a 64-bit LCG with explicitly chosen stream with the PCG-XSH-RR
output function. This combination is the standard `pcg32`

.

Despite the name, this implementation uses 16 bytes (128 bit) space
comprising 64 bits of state and 64 bits stream selector. These are both set
by `SeedableRng`

, using a 128-bit seed.

Note that two generators with different stream parameter may be closely correlated.

## Implementations§

source§### impl Lcg64Xsh32

### impl Lcg64Xsh32

source#### pub fn advance(&mut self, delta: u64)

#### pub fn advance(&mut self, delta: u64)

Multi-step advance functions (jump-ahead, jump-back)

The method used here is based on Brown, “Random Number Generation with Arbitrary Stride,”, Transactions of the American Nuclear Society (Nov. 1994). The algorithm is very similar to fast exponentiation.

Even though delta is an unsigned integer, we can pass a signed integer to go backwards, it just goes “the long way round”.

Using this function is equivalent to calling `next_32()`

`delta`

number of times.

source#### pub fn new(state: u64, stream: u64) -> Self

#### pub fn new(state: u64, stream: u64) -> Self

Construct an instance compatible with PCG seed and stream.

Note that the highest bit of the `stream`

parameter is discarded
to simplify upholding internal invariants.

Note that two generators with different stream parameters may be closely correlated.

PCG specifies the following default values for both parameters:

`state = 0xcafef00dd15ea5e5`

`stream = 0xa02bdbf7bb3c0a7`

## Trait Implementations§

source§### impl Clone for Lcg64Xsh32

### impl Clone for Lcg64Xsh32

source§#### fn clone(&self) -> Lcg64Xsh32

#### fn clone(&self) -> Lcg64Xsh32

1.0.0 · source§#### fn clone_from(&mut self, source: &Self)

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

`source`

. Read moresource§### impl Debug for Lcg64Xsh32

### impl Debug for Lcg64Xsh32

source§### impl<'de> Deserialize<'de> for Lcg64Xsh32

### impl<'de> Deserialize<'de> for Lcg64Xsh32

source§#### fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>where
__D: Deserializer<'de>,

#### fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>where
__D: Deserializer<'de>,

source§### impl PartialEq for Lcg64Xsh32

### impl PartialEq for Lcg64Xsh32

source§#### fn eq(&self, other: &Lcg64Xsh32) -> bool

#### fn eq(&self, other: &Lcg64Xsh32) -> bool

`self`

and `other`

values to be equal, and is used
by `==`

.source§### impl RngCore for Lcg64Xsh32

### impl RngCore for Lcg64Xsh32

source§### impl SeedableRng for Lcg64Xsh32

### impl SeedableRng for Lcg64Xsh32

source§#### fn from_seed(seed: Self::Seed) -> Self

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

We use a single 127-bit seed to initialise the state and select a stream.
One `seed`

bit (lowest bit of `seed[8]`

) is ignored.

§#### type Seed = [u8; 16]

#### type Seed = [u8; 16]

`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§#### fn from_rng(rng: impl RngCore) -> Self

#### fn from_rng(rng: impl RngCore) -> Self

`Rng`

. Read moresource§#### fn try_from_rng<R>(rng: R) -> Result<Self, <R as TryRngCore>::Error>where
R: TryRngCore,

#### fn try_from_rng<R>(rng: R) -> Result<Self, <R as TryRngCore>::Error>where
R: TryRngCore,

`Rng`

. Read moresource§#### fn from_os_rng() -> Self

#### fn from_os_rng() -> Self

source§### impl Serialize for Lcg64Xsh32

### impl Serialize for Lcg64Xsh32

### impl Eq for Lcg64Xsh32

### impl StructuralPartialEq for Lcg64Xsh32

## Auto Trait Implementations§

### impl Freeze for Lcg64Xsh32

### impl RefUnwindSafe for Lcg64Xsh32

### impl Send for Lcg64Xsh32

### impl Sync for Lcg64Xsh32

### impl Unpin for Lcg64Xsh32

### impl UnwindSafe for Lcg64Xsh32

## Blanket Implementations§

source§### impl<T> BorrowMut<T> for Twhere
T: ?Sized,

### impl<T> BorrowMut<T> for Twhere
T: ?Sized,

source§#### fn borrow_mut(&mut self) -> &mut T

#### fn borrow_mut(&mut self) -> &mut T

source§### impl<T> CloneToUninit for Twhere
T: Clone,

### impl<T> CloneToUninit for Twhere
T: Clone,

source§#### default unsafe fn clone_to_uninit(&self, dst: *mut T)

#### default unsafe fn clone_to_uninit(&self, dst: *mut T)

`clone_to_uninit`

)