Struct soroban_sdk::prng::Prng

impl Prng

pub fn env(&self) -> &Env

pub fn seed(&self, seed: Bytes)

Reseeds the PRNG with the provided value.

The seed is combined with the seed assigned to the contract invocation.

Warning

The PRNG is unsuitable for generating secrets or use in applications with low risk tolerance, see the module-level comment.

pub fn u64_in_range(&self, r: impl RangeBounds<u64>) -> u64

Returns a random u64 in the range specified.

Panics

If the range is empty.

Warning

The PRNG is unsuitable for generating secrets or use in applications with low risk tolerance, see the module-level comment.

Examples

use soroban_sdk::{Env};

// Get values in the range of 1 to 100, inclusive.
let value = env.prng().u64_in_range(1..=100);
assert_eq!(value, 77);
let value = env.prng().u64_in_range(1..=100);
assert_eq!(value, 66);
let value = env.prng().u64_in_range(1..=100);
assert_eq!(value, 72);

pub fn shuffle<V>(&self, v: V) -> Vec<Val>
where V: IntoVal<Env, Vec<Val>>,

Shuffles a given vector v using the Fisher-Yates algorithm.

Warning

The PRNG is unsuitable for generating secrets or use in applications with low risk tolerance, see the module-level comment.

Auto Trait Implementations§

impl !UnwindSafe for Prng

Blanket Implementations§

impl<T> Any for T
where T: 'static + ?Sized,

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

impl<T> Borrow<T> for T
where T: ?Sized,

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

impl<T> BorrowMut<T> for T
where T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

impl<T, C> Compare<&T> for C
where C: Compare<T>,

type Error = <C as Compare<T>>::Error

fn compare(&self, a: &&T, b: &&T) -> Result<Ordering, <C as Compare<&T>>::Error>

impl<T, U, E, C> Compare<(T, U)> for C
where C: Compare<T, Error = E, Error = E> + Compare,

type Error = E

fn compare( &self, a: &(T, U), b: &(T, U) ) -> Result<Ordering, <C as Compare<(T, U)>>::Error>

impl<T, U, V, E, C> Compare<(T, U, V)> for C
where C: Compare<T, Error = E, Error = E, Error = E> + Compare + Compare<V>,

type Error = E

fn compare( &self, a: &(T, U, V), b: &(T, U, V) ) -> Result<Ordering, <C as Compare<(T, U, V)>>::Error>

impl<T, U, V, W, E, C> Compare<(T, U, V, W)> for C
where C: Compare<T, Error = E, Error = E, Error = E, Error = E> + Compare + Compare<V> + Compare<W>,

type Error = E

fn compare( &self, a: &(T, U, V, W), b: &(T, U, V, W) ) -> Result<Ordering, <C as Compare<(T, U, V, W)>>::Error>

impl<T, U, V, W, X, E, C> Compare<(T, U, V, W, X)> for C
where C: Compare<T, Error = E, Error = E, Error = E, Error = E, Error = E> + Compare + Compare<V> + Compare<W> + Compare<X>,

type Error = E

fn compare( &self, a: &(T, U, V, W, X), b: &(T, U, V, W, X) ) -> Result<Ordering, <C as Compare<(T, U, V, W, X)>>::Error>

impl<T, C> Compare<Box<T>> for C
where C: Compare<T>,

type Error = <C as Compare<T>>::Error

fn compare( &self, a: &Box<T>, b: &Box<T> ) -> Result<Ordering, <C as Compare<Box<T>>>::Error>

impl<T, C> Compare<Option<T>> for C
where C: Compare<T>,

type Error = <C as Compare<T>>::Error

fn compare( &self, a: &Option<T>, b: &Option<T> ) -> Result<Ordering, <C as Compare<Option<T>>>::Error>

impl<T, C> Compare<Rc<T>> for C
where C: Compare<T>,

type Error = <C as Compare<T>>::Error

fn compare( &self, a: &Rc<T>, b: &Rc<T> ) -> Result<Ordering, <C as Compare<Rc<T>>>::Error>

impl<T, C> Compare<Vec<T>> for C
where C: Compare<T>,

type Error = <C as Compare<T>>::Error

fn compare( &self, a: &Vec<T>, b: &Vec<T> ) -> Result<Ordering, <C as Compare<Vec<T>>>::Error>

impl<T> Downcast for T
where T: Any,

fn into_any(self: Box<T>) -> Box<dyn Any>

Convert Box<dyn Trait> (where Trait: Downcast) to Box<dyn Any>. Box<dyn Any> can then be further downcast into Box<ConcreteType> where ConcreteType implements Trait.

fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>

Convert Rc<Trait> (where Trait: Downcast) to Rc<Any>. Rc<Any> can then be further downcast into Rc<ConcreteType> where ConcreteType implements Trait.