# [−][src]Struct rand::StdRng

    pub struct StdRng { /* fields omitted */ }

The standard RNG. This is designed to be efficient on the current platform.

## Methods

### `impl StdRng`[src]

#### `pub fn new() -> Result<StdRng>`[src]

Create a randomly seeded instance of `StdRng`.

This is a very expensive operation as it has to read randomness from the operating system and use this in an expensive seeding operation. If one is only generating a small number of random numbers, or doesn't need the utmost speed for generating each number, `thread_rng` and/or `random` may be more appropriate.

Reading the randomness from the OS may fail, and any error is propagated via the `io::Result` return value.

## Trait Implementations

### `impl Rng for StdRng`[src]

#### `fn next_u32(&mut self) -> u32`[src]

Return the next random u32. Read more

#### `fn next_u64(&mut self) -> u64`[src]

Return the next random u64. Read more

#### `fn next_f32(&mut self) -> f32`[src]

Return the next random f32 selected from the half-open interval `[0, 1)`. Read more

#### `fn next_f64(&mut self) -> f64`[src]

Return the next random f64 selected from the half-open interval `[0, 1)`. Read more

#### `fn fill_bytes(&mut self, dest: &mut [u8])`[src]

Fill `dest` with random data. Read more

#### `fn gen<T: Rand>(&mut self) -> T where
Self: Sized,` [src]

Return a random value of a `Rand` type. Read more

####
ⓘImportant traits for Generator<'a, T, R>

### Important traits for Generator<'a, T, R>

`impl<'a, T: Rand, R: Rng> Iterator for Generator<'a, T, R> type Item = T;`
`fn gen_iter<'a, T: Rand>(&'a mut self) -> Generator<'a, T, Self> where
Self: Sized,` [src]

Return an iterator that will yield an infinite number of randomly generated items. Read more

#### `fn gen_range<T: PartialOrd + SampleRange>(&mut self, low: T, high: T) -> T where
Self: Sized,` [src]

Generate a random value in the range [`low`, `high`). Read more

#### `fn gen_weighted_bool(&mut self, n: u32) -> bool where
Self: Sized,` [src]

Return a bool with a 1 in n chance of true Read more

####
ⓘImportant traits for AsciiGenerator<'a, R>

### Important traits for AsciiGenerator<'a, R>

`impl<'a, R: Rng> Iterator for AsciiGenerator<'a, R> type Item = char;`
`fn gen_ascii_chars<'a>(&'a mut self) -> AsciiGenerator<'a, Self> where
Self: Sized,` [src]

Return an iterator of random characters from the set A-Z,a-z,0-9. Read more

#### `fn choose<'a, T>(&mut self, values: &'a [T]) -> Option<&'a T> where
Self: Sized,` [src]

Return a random element from `values`. Read more

#### `fn choose_mut<'a, T>(&mut self, values: &'a mut [T]) -> Option<&'a mut T> where
Self: Sized,` [src]

Return a mutable pointer to a random element from `values`. Read more

#### `fn shuffle<T>(&mut self, values: &mut [T]) where
Self: Sized,` [src]

Shuffle a mutable slice in place. Read more

### `impl<'a> SeedableRng<&'a [usize]> for StdRng`[src]

#### `fn reseed(&mut self, seed: &'a [usize])`[src]

Reseed an RNG with the given seed. Read more

#### `fn from_seed(seed: &'a [usize]) -> StdRng`[src]

Create a new RNG with the given seed. Read more

### `impl Clone for StdRng`[src]

#### `fn clone(&self) -> StdRng`[src]

Returns a copy of the value. Read more

#### `fn clone_from(&mut self, source: &Self)`1.0.0[src]

Performs copy-assignment from `source`. Read more

### `impl Copy for StdRng`[src]

### `impl Debug for StdRng`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result`[src]

Formats the value using the given formatter. Read more

## Auto Trait Implementations

### `impl Send for StdRng`

### `impl Unpin for StdRng`

### `impl Sync for StdRng`

### `impl UnwindSafe for StdRng`

### `impl RefUnwindSafe for StdRng`

## Blanket Implementations

### `impl<T> ToOwned for T where
T: Clone,` [src]

#### `type Owned = T`

The resulting type after obtaining ownership.

#### `fn to_owned(&self) -> T`[src]

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

#### `fn clone_into(&self, target: &mut T)`[src]

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

recently added

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

### `impl<T, U> Into<U> for T where
U: From<T>,` [src]

#### `fn into(self) -> U`[src]

Performs the conversion.

### `impl<T> From<T> for T`[src]

#### `fn from(t: T) -> T`[src]

Performs the conversion.

### `impl<T, U> TryFrom<U> for T where
U: Into<T>,` [src]

#### `type Error = Infallible`

The type returned in the event of a conversion error.

#### `fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>`[src]

Performs the conversion.

### `impl<T, U> TryInto<U> for T where
U: TryFrom<T>,` [src]

#### `type Error = <U as TryFrom<T>>::Error`

The type returned in the event of a conversion error.

#### `fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>`[src]

Performs the conversion.

### `impl<T> BorrowMut<T> for T where
T: ?Sized,` [src]

#### `fn borrow_mut(&mut self) -> &mut T`[src]

Mutably borrows from an owned value. Read more

### `impl<T> Borrow<T> for T where
T: ?Sized,` [src]

#### `fn borrow(&self) -> &T`[src]

Immutably borrows from an owned value. Read more

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `fn type_id(&self) -> TypeId`[src]

Gets the `TypeId` of `self`. Read more

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