Struct Probability 

pub struct Probability(/* private fields */);

A probability represented as a threshold over all possible u64 samples.

Ratios are rounded down to the nearest multiple of 2^-64. Sampling consumes one u64 for probabilities strictly between zero and one, and consumes no randomness for either endpoint. Given the same sequence of u64 samples, decisions are identical on every platform.

Implementations

impl Probability

pub const fn new(numerator: u64, denominator: u64) -> Option<Self>

Creates a probability from numerator / denominator.

Returns None if the denominator is zero or the numerator exceeds the denominator.

pub const fn from_f64(value: f64) -> Option<Self>

Creates a probability from an f64 that maps exactly to a 64-bit threshold.

Returns None if value is not finite, is outside [0, 1], or would require rounding. The exact IEEE-754 value is preserved rather than interpreting its source spelling as a decimal ratio. Use TryFrom when const evaluation is not required.

pub const fn is_zero(self) -> bool

Returns whether this probability never occurs.

pub const fn is_one(self) -> bool

Returns whether this probability always occurs.

pub fn as_f64(self) -> f64

Converts this probability to an f64 in the inclusive range [0, 1].

This conversion is intended for APIs that require floating-point probabilities. Interior probabilities remain strictly below one even when rounding to f64.

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

Samples this probability using the next u64 from rng.

Trait Implementations

impl Clone for Probability

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Probability

impl Debug for Probability

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

Formats the value using the given formatter.

impl Eq for Probability

impl Hash for Probability

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for Probability

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

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

Restrict a value to a certain range.

impl PartialEq for Probability

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialOrd for Probability

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for Probability

impl TryFrom<f64> for Probability

type Error = InvalidProbability

The type returned in the event of a conversion error.

fn try_from(value: f64) -> Result<Self, Self::Error>

Performs the conversion.