Struct rand::rngs::OsRng[][src]

pub struct OsRng;
This is supported on crate feature getrandom only.
Expand description

A random number generator that retrieves randomness from the operating system.

This is a zero-sized struct. It can be freely constructed with OsRng.

The implementation is provided by the getrandom crate. Refer to getrandom documentation for details.

This struct is only available when specifying the crate feature getrandom or std. When using the rand lib, it is also available as rand::rngs::OsRng.

Blocking and error handling

It is possible that when used during early boot the first call to OsRng will block until the system’s RNG is initialised. It is also possible (though highly unlikely) for OsRng to fail on some platforms, most likely due to system mis-configuration.

After the first successful call, it is highly unlikely that failures or significant delays will occur (although performance should be expected to be much slower than a user-space PRNG).

Usage example

use rand_core::{RngCore, OsRng};

let mut key = [0u8; 16];
OsRng.fill_bytes(&mut key);
let random_u64 = OsRng.next_u64();

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Returns the “default value” for a type. Read more

Return the next random u32. Read more

Return the next random u64. Read more

Fill dest with random data. Read more

Fill dest entirely with random data. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Upcast to an RngCore trait object.

Performs the conversion.

Performs the conversion.

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

🔬 This is a nightly-only experimental API. (toowned_clone_into)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.