Trait rand::TryRngCore

pub trait TryRngCore {
    type Error: Debug + Display;

    // Required methods
    fn try_next_u32(&mut self) -> Result<u32, Self::Error>;
    fn try_next_u64(&mut self) -> Result<u64, Self::Error>;
    fn try_fill_bytes(&mut self, dst: &mut [u8]) -> Result<(), Self::Error>;

    // Provided methods
    fn unwrap_err(self) -> UnwrapErr<Self>
       where Self: Sized { ... }
    fn read_adapter(&mut self) -> RngReadAdapter<'_, Self>
       where Self: Sized { ... }
}

A potentially fallible version of RngCore.

This trait is primarily used for IO-based generators such as OsRng.

Most of higher-level generic code in the rand crate is built on top of the the RngCore trait. Users can transform a fallible RNG (i.e. TryRngCore implementor) into an “infallible” (but potentially panicking) RNG (i.e. RngCore implementor) using the UnwrapErr wrapper.

RngCore implementors also usually implement TryRngCore with the Error associated type being equal to Infallible. In other words, users can use TryRngCore to generalize over fallible and infallible RNGs.

Required Associated Types

type Error: Debug + Display

The type returned in the event of a RNG error.

Required Methods

fn try_next_u32(&mut self) -> Result<u32, Self::Error>

Return the next random u32.

fn try_next_u64(&mut self) -> Result<u64, Self::Error>

Return the next random u64.

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

Fill dest entirely with random data.

Provided Methods

fn unwrap_err(self) -> UnwrapErr<Self>

where Self: Sized,

Wrap RNG with the UnwrapErr wrapper.

fn read_adapter(&mut self) -> RngReadAdapter<'_, Self>

where Self: Sized,

Convert an RngCore to a RngReadAdapter.

Implementations on Foreign Types

impl TryRngCore for ChaCha8Rng

type Error = Infallible

fn try_next_u32(&mut self) -> Result<u32, <ChaCha8Rng as TryRngCore>::Error>

fn try_next_u64(&mut self) -> Result<u64, <ChaCha8Rng as TryRngCore>::Error>

fn try_fill_bytes( &mut self, dst: &mut [u8] ) -> Result<(), <ChaCha8Rng as TryRngCore>::Error>

impl TryRngCore for ChaCha12Rng

type Error = Infallible

fn try_next_u32(&mut self) -> Result<u32, <ChaCha12Rng as TryRngCore>::Error>

fn try_next_u64(&mut self) -> Result<u64, <ChaCha12Rng as TryRngCore>::Error>

fn try_fill_bytes( &mut self, dst: &mut [u8] ) -> Result<(), <ChaCha12Rng as TryRngCore>::Error>

impl TryRngCore for ChaCha20Rng

type Error = Infallible

fn try_next_u32(&mut self) -> Result<u32, <ChaCha20Rng as TryRngCore>::Error>

fn try_next_u64(&mut self) -> Result<u64, <ChaCha20Rng as TryRngCore>::Error>

fn try_fill_bytes( &mut self, dst: &mut [u8] ) -> Result<(), <ChaCha20Rng as TryRngCore>::Error>

impl<'a, R> TryRngCore for &'a mut R

where R: TryRngCore + ?Sized,

type Error = <R as TryRngCore>::Error

fn try_next_u32(&mut self) -> Result<u32, <&'a mut R as TryRngCore>::Error>

fn try_next_u64(&mut self) -> Result<u64, <&'a mut R as TryRngCore>::Error>

fn try_fill_bytes( &mut self, dst: &mut [u8] ) -> Result<(), <&'a mut R as TryRngCore>::Error>

impl<R> TryRngCore for Box<R>

where R: TryRngCore + ?Sized,

type Error = <R as TryRngCore>::Error

fn try_next_u32(&mut self) -> Result<u32, <Box<R> as TryRngCore>::Error>

fn try_next_u64(&mut self) -> Result<u64, <Box<R> as TryRngCore>::Error>

fn try_fill_bytes( &mut self, dst: &mut [u8] ) -> Result<(), <Box<R> as TryRngCore>::Error>

Implementors

impl TryRngCore for StepRng

type Error = Infallible

impl TryRngCore for OsRng

type Error = Error

impl TryRngCore for SmallRng

type Error = Infallible

impl TryRngCore for StdRng

type Error = Infallible

impl TryRngCore for ThreadRng

type Error = Infallible