Struct rand_core::impls::BlockRng

pub struct BlockRng<R: BlockRngCore + ?Sized> {
    pub results: R::Results,
    pub index: usize,
    pub core: R,
}

Wrapper around PRNGs that implement BlockRngCore to keep a results buffer and offer the methods from RngCore.

BlockRng has heavily optimized implementations of the RngCore methods reading values from the results buffer, as well as calling BlockRngCore::generate directly on the output array when fill_bytes / try_fill_bytes is called on a large array. These methods also handle the bookkeeping of when to generate a new batch of values. No generated values are ever thown away.

Currently BlockRng only implements RngCore for buffers which are slices of u32 elements; this may be extended to other types in the future.

For easy initialization BlockRng also implements SeedableRng.

Fields

results: R::Results

index: usize

core: R

Trait Implementations

impl<R: Clone + BlockRngCore + ?Sized> Clone for BlockRng<R> where
    R::Results: Clone, 

fn clone(&self) -> BlockRng<R>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<R: BlockRngCore + Debug> Debug for BlockRng<R>

fn fmt(&self, fmt: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<R: BlockRngCore<Item = u32>> RngCore for BlockRng<R> where
    <R as BlockRngCore>::Results: AsRef<[u32]>, 

fn next_u32(&mut self) -> u32

Return the next random u32.

fn next_u64(&mut self) -> u64

Return the next random u64.

fn fill_bytes(&mut self, dest: &mut [u8])

Fill dest with random data.

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

Fill dest entirely with random data.

impl<R: BlockRngCore + SeedableRng> SeedableRng for BlockRng<R>

type Seed = R::Seed

Seed type, which is restricted to types mutably-dereferencable 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 from_rng<S: RngCore>(rng: S) -> Result<Self, Error>

Create a new PRNG seeded from another Rng.

impl<R: BlockRngCore + CryptoRng> CryptoRng for BlockRng<R>