Struct rand::rngs::ThreadRng

[+] Show declaration

pub struct ThreadRng { /* fields omitted */ }

[−] Expand description

The type returned by thread_rng, essentially just a reference to the PRNG in thread-local memory.

ThreadRng uses ReseedingRng wrapping the same PRNG as StdRng, which is reseeded after generating 32 MiB of random data. A single instance is cached per thread and the returned ThreadRng is a reference to this instance — hence ThreadRng is neither Send nor Sync but is safe to use within a single thread. This RNG is seeded and reseeded via EntropyRng as required.

Note that the reseeding is done as an extra precaution against entropy leaks and is in theory unnecessary — to predict ThreadRng's output, an attacker would have to either determine most of the RNG's seed or internal state, or crack the algorithm used.

Like StdRng, ThreadRng is a cryptographically secure PRNG. The current algorithm used is HC-128, which is an array-based PRNG that trades memory usage for better performance. This makes it similar to ISAAC, the algorithm used in ThreadRng before rand 0.5.

Cloning this handle just produces a new reference to the same thread-local generator.

Trait Implementations

impl Clone for ThreadRng

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fn clone(&self) -> ThreadRng

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Returns a copy of the value.

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

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Performs copy-assignment from source.

impl Debug for ThreadRng

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

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Formats the value using the given formatter.

impl RngCore for ThreadRng

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fn next_u32(&mut self) -> u32

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Return the next random u32.

fn next_u64(&mut self) -> u64

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Return the next random u64.

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

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Fill dest with random data.

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

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Fill dest entirely with random data.

impl CryptoRng for ThreadRng