Struct urandom::distributions::Standard

pub struct Standard;

A generic random value distribution, implemented for many primitive types. Usually generates values with a numerically uniform distribution, and with a range appropriate to the type.

Provided implementations

Assuming the provided Rng is well-behaved, these implementations generate values with the following ranges and distributions:

• Integers (i32, u32, isize, usize, etc.): Uniformly distributed over all values of the type.
• char: Uniformly distributed over all Unicode scalar values, i.e. all code points in the range 0..0x11_0000, except for the range 0xD800..0xE000 (the surrogate code points). This includes unassigned/reserved code points.
• bool: Generates true or false, each with equal probability.
• Floating point types (f32 and f64): Uniformly distributed in the half-open interval [1.0, 2.0). See notes below.
• Wrapping integers (Wrapping<T>), besides the type identical to their normal integer variants.

The Standard distribution also supports generation of the following compound types where all component types are supported:

• Tuples (up to 12 elements): each element is generated sequentially.
• Arrays (up to 32 elements): each element is generated sequentially; see also Random::fill which supports arbitrary array length for integer types and tends to be faster for u32 and smaller types.

Examples

use urandom::distributions::Standard;

let val: f32 = urandom::new().sample(&Standard);
assert!(val >= 1.0 && val < 2.0, "f32 from [1.0, 2.0): {}", val);

Custom implementations

The Standard distribution may be implemented for user types as follows:

use urandom::{Random, Rng, Distribution, distributions::Standard};

struct MyF32(f32);

impl Distribution<MyF32> for Standard {
	fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> MyF32 {
		MyF32(rng.next())
	}
}

Floating point implementation

The floating point implementations for Standard generate a random value in the half-open interval [1.0, 2.0), i.e. including 1.0 but not 2.0.

The random value is generated by transmuting a random mantissa with a fixed exponent which is very fast and convenient. The underlying Rng can optimize generating random floating point values as they don’t need every random bit of the underlying u32 or u64.

This is equivalent to calling Random::next_f32 and Random::next_f64 directly.

Subtracting 1.0 is an easy way to get a random floating point value in the half-open interval [0.0, 1.0) but has a small bias where it will never generate certain floating point values. This is equivalent to rng.range(0.0..1.0).

See also: Float01 which samples from (0.0, 1.0) and does not suffer from this bias.

Trait Implementations

impl Clone for Standard

fn clone(&self) -> Standard

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Standard

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

Formats the value using the given formatter.

impl<T> Distribution<[T; 0]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 0]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 1]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 1]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 10]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 10]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 11]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 11]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 12]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 12]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 13]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 13]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 14]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 14]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 15]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 15]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 16]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 16]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 17]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 17]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 18]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 18]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 19]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 19]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 2]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 2]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 20]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 20]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 21]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 21]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 22]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 22]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 23]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 23]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 24]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 24]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 25]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 25]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 26]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 26]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 27]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 27]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 28]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 28]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 29]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 29]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 3]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 3]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 30]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 30]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 31]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 31]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 32]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 32]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 4]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 4]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 5]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 5]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 6]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 6]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 7]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 7]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 8]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 8]

Generate a random value of T, using rng as the source of randomness.

impl<T> Distribution<[T; 9]> for Standardwhere
    Standard: Distribution<T>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> [T; 9]

Generate a random value of T, using rng as the source of randomness.

impl Distribution<()> for Standard

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>)

Generate a random value of T, using rng as the source of randomness.

impl<A, B, C, D, E, F, G, H, I, J, K, L> Distribution<(A, B, C, D, E, F, G, H, I, J, K, L)> for Standardwhere
    Standard: Distribution<A>,
    Standard: Distribution<B>,
    Standard: Distribution<C>,
    Standard: Distribution<D>,
    Standard: Distribution<E>,
    Standard: Distribution<F>,
    Standard: Distribution<G>,
    Standard: Distribution<H>,
    Standard: Distribution<I>,
    Standard: Distribution<J>,
    Standard: Distribution<K>,
    Standard: Distribution<L>,

fn sample<R: Rng + ?Sized>(
    &self,
    _rng: &mut Random<R>
) -> (A, B, C, D, E, F, G, H, I, J, K, L)

Generate a random value of T, using rng as the source of randomness.

impl<A, B, C, D, E, F, G, H, I, J, K> Distribution<(A, B, C, D, E, F, G, H, I, J, K)> for Standardwhere
    Standard: Distribution<A>,
    Standard: Distribution<B>,
    Standard: Distribution<C>,
    Standard: Distribution<D>,
    Standard: Distribution<E>,
    Standard: Distribution<F>,
    Standard: Distribution<G>,
    Standard: Distribution<H>,
    Standard: Distribution<I>,
    Standard: Distribution<J>,
    Standard: Distribution<K>,

fn sample<R: Rng + ?Sized>(
    &self,
    _rng: &mut Random<R>
) -> (A, B, C, D, E, F, G, H, I, J, K)

Generate a random value of T, using rng as the source of randomness.

impl<A, B, C, D, E, F, G, H, I, J> Distribution<(A, B, C, D, E, F, G, H, I, J)> for Standardwhere
    Standard: Distribution<A>,
    Standard: Distribution<B>,
    Standard: Distribution<C>,
    Standard: Distribution<D>,
    Standard: Distribution<E>,
    Standard: Distribution<F>,
    Standard: Distribution<G>,
    Standard: Distribution<H>,
    Standard: Distribution<I>,
    Standard: Distribution<J>,

fn sample<R: Rng + ?Sized>(
    &self,
    _rng: &mut Random<R>
) -> (A, B, C, D, E, F, G, H, I, J)

Generate a random value of T, using rng as the source of randomness.

impl<A, B, C, D, E, F, G, H, I> Distribution<(A, B, C, D, E, F, G, H, I)> for Standardwhere
    Standard: Distribution<A>,
    Standard: Distribution<B>,
    Standard: Distribution<C>,
    Standard: Distribution<D>,
    Standard: Distribution<E>,
    Standard: Distribution<F>,
    Standard: Distribution<G>,
    Standard: Distribution<H>,
    Standard: Distribution<I>,

fn sample<R: Rng + ?Sized>(
    &self,
    _rng: &mut Random<R>
) -> (A, B, C, D, E, F, G, H, I)

Generate a random value of T, using rng as the source of randomness.

impl<A, B, C, D, E, F, G, H> Distribution<(A, B, C, D, E, F, G, H)> for Standardwhere
    Standard: Distribution<A>,
    Standard: Distribution<B>,
    Standard: Distribution<C>,
    Standard: Distribution<D>,
    Standard: Distribution<E>,
    Standard: Distribution<F>,
    Standard: Distribution<G>,
    Standard: Distribution<H>,

fn sample<R: Rng + ?Sized>(
    &self,
    _rng: &mut Random<R>
) -> (A, B, C, D, E, F, G, H)

Generate a random value of T, using rng as the source of randomness.

impl<A, B, C, D, E, F, G> Distribution<(A, B, C, D, E, F, G)> for Standardwhere
    Standard: Distribution<A>,
    Standard: Distribution<B>,
    Standard: Distribution<C>,
    Standard: Distribution<D>,
    Standard: Distribution<E>,
    Standard: Distribution<F>,
    Standard: Distribution<G>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> (A, B, C, D, E, F, G)

Generate a random value of T, using rng as the source of randomness.

impl<A, B, C, D, E, F> Distribution<(A, B, C, D, E, F)> for Standardwhere
    Standard: Distribution<A>,
    Standard: Distribution<B>,
    Standard: Distribution<C>,
    Standard: Distribution<D>,
    Standard: Distribution<E>,
    Standard: Distribution<F>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> (A, B, C, D, E, F)

Generate a random value of T, using rng as the source of randomness.

impl<A, B, C, D, E> Distribution<(A, B, C, D, E)> for Standardwhere
    Standard: Distribution<A>,
    Standard: Distribution<B>,
    Standard: Distribution<C>,
    Standard: Distribution<D>,
    Standard: Distribution<E>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> (A, B, C, D, E)

Generate a random value of T, using rng as the source of randomness.

impl<A, B, C, D> Distribution<(A, B, C, D)> for Standardwhere
    Standard: Distribution<A>,
    Standard: Distribution<B>,
    Standard: Distribution<C>,
    Standard: Distribution<D>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> (A, B, C, D)

Generate a random value of T, using rng as the source of randomness.

impl<A, B, C> Distribution<(A, B, C)> for Standardwhere
    Standard: Distribution<A>,
    Standard: Distribution<B>,
    Standard: Distribution<C>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> (A, B, C)

Generate a random value of T, using rng as the source of randomness.

impl<A, B> Distribution<(A, B)> for Standardwhere
    Standard: Distribution<A>,
    Standard: Distribution<B>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> (A, B)

Generate a random value of T, using rng as the source of randomness.

impl<A> Distribution<(A,)> for Standardwhere
    Standard: Distribution<A>,

fn sample<R: Rng + ?Sized>(&self, _rng: &mut Random<R>) -> (A,)

Generate a random value of T, using rng as the source of randomness.

impl Distribution<NonZeroU128> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> NonZeroU128

Generate a random value of T, using rng as the source of randomness.

impl Distribution<NonZeroU16> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> NonZeroU16

Generate a random value of T, using rng as the source of randomness.

impl Distribution<NonZeroU32> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> NonZeroU32

Generate a random value of T, using rng as the source of randomness.

impl Distribution<NonZeroU64> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> NonZeroU64

Generate a random value of T, using rng as the source of randomness.

impl Distribution<NonZeroU8> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> NonZeroU8

Generate a random value of T, using rng as the source of randomness.

impl Distribution<NonZeroUsize> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> NonZeroUsize

Generate a random value of T, using rng as the source of randomness.

impl Distribution<bool> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> bool

Generate a random value of T, using rng as the source of randomness.

impl Distribution<char> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> char

Generate a random value of T, using rng as the source of randomness.

impl Distribution<f32> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> f32

Generate a random value of T, using rng as the source of randomness.

impl Distribution<f64> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> f64

Generate a random value of T, using rng as the source of randomness.

impl Distribution<i128> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> i128

Generate a random value of T, using rng as the source of randomness.

impl Distribution<i16> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> i16

Generate a random value of T, using rng as the source of randomness.

impl Distribution<i32> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> i32

Generate a random value of T, using rng as the source of randomness.

impl Distribution<i64> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> i64

Generate a random value of T, using rng as the source of randomness.

impl Distribution<i8> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> i8

Generate a random value of T, using rng as the source of randomness.

impl Distribution<isize> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> isize

Generate a random value of T, using rng as the source of randomness.

impl Distribution<u128> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> u128

Generate a random value of T, using rng as the source of randomness.

impl Distribution<u16> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> u16

Generate a random value of T, using rng as the source of randomness.

impl Distribution<u32> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> u32

Generate a random value of T, using rng as the source of randomness.

impl Distribution<u64> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> u64

Generate a random value of T, using rng as the source of randomness.

impl Distribution<u8> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> u8

Generate a random value of T, using rng as the source of randomness.

impl Distribution<usize> for Standard

fn sample<R: Rng + ?Sized>(&self, rng: &mut Random<R>) -> usize

Generate a random value of T, using rng as the source of randomness.

impl Copy for Standard