pub struct ThreadRng { /* private fields */ }
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§
source§impl RngCore for ThreadRng
impl RngCore for ThreadRng
source§fn fill_bytes(&mut self, dest: &mut [u8])
fn fill_bytes(&mut self, dest: &mut [u8])
dest
with random data. Read moreimpl CryptoRng for ThreadRng
Auto Trait Implementations§
impl !RefUnwindSafe for ThreadRng
impl !Send for ThreadRng
impl !Sync for ThreadRng
impl Unpin for ThreadRng
impl !UnwindSafe for ThreadRng
Blanket Implementations§
source§impl<R> Rng for Rwhere
R: RngCore + ?Sized,
impl<R> Rng for Rwhere
R: RngCore + ?Sized,
source§fn gen<T>(&mut self) -> Twhere
Standard: Distribution<T>,
fn gen<T>(&mut self) -> Twhere
Standard: Distribution<T>,
source§fn gen_range<T>(&mut self, low: T, high: T) -> Twhere
T: PartialOrd<T> + SampleUniform,
fn gen_range<T>(&mut self, low: T, high: T) -> Twhere
T: PartialOrd<T> + SampleUniform,
low
, high
), i.e. inclusive of
low
and exclusive of high
. Read moresource§fn sample<T, D>(&mut self, distr: D) -> Twhere
D: Distribution<T>,
fn sample<T, D>(&mut self, distr: D) -> Twhere
D: Distribution<T>,
source§fn sample_iter<T, D, 'a>(&'a mut self, distr: &'a D) -> DistIter<'a, D, Self, T>where
D: Distribution<T>,
Self: Sized,
fn sample_iter<T, D, 'a>(&'a mut self, distr: &'a D) -> DistIter<'a, D, Self, T>where
D: Distribution<T>,
Self: Sized,
source§fn fill<T>(&mut self, dest: &mut T)where
T: AsByteSliceMut + ?Sized,
fn fill<T>(&mut self, dest: &mut T)where
T: AsByteSliceMut + ?Sized,
dest
entirely with random bytes (uniform value distribution),
where dest
is any type supporting AsByteSliceMut
, namely slices
and arrays over primitive integer types (i8
, i16
, u32
, etc.). Read moresource§fn try_fill<T>(&mut self, dest: &mut T) -> Result<(), Error>where
T: AsByteSliceMut + ?Sized,
fn try_fill<T>(&mut self, dest: &mut T) -> Result<(), Error>where
T: AsByteSliceMut + ?Sized,
dest
entirely with random bytes (uniform value distribution),
where dest
is any type supporting AsByteSliceMut
, namely slices
and arrays over primitive integer types (i8
, i16
, u32
, etc.). Read moresource§fn gen_bool(&mut self, p: f64) -> bool
fn gen_bool(&mut self, p: f64) -> bool
p
of being true. Read moresource§fn choose<T, 'a>(&mut self, values: &'a [T]) -> Option<&'a T>
fn choose<T, 'a>(&mut self, values: &'a [T]) -> Option<&'a T>
values
. Read moresource§fn choose_mut<T, 'a>(&mut self, values: &'a mut [T]) -> Option<&'a mut T>
fn choose_mut<T, 'a>(&mut self, values: &'a mut [T]) -> Option<&'a mut T>
values
. Read more