# futures_util::stream::Peek - Rust
API documentation for the Rust `Peek` struct in crate `futures_util`.
Keywords: rust, rustlang, rust-lang, Peek

# [−] [src] Struct futures_util::stream::Peek

    #[must_use = "futures do nothing unless polled"]pub struct Peek<'a, St: Stream> { /* fields omitted */ }

Future for the `Peekable::peek()` function from `Peekable`

## Trait Implementations

### `impl<St> Debug for Peek<'_, St> where
St: Stream + Debug,
St::Item: Debug,` [src]

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

Formats the value using the given formatter. Read more

### `impl<St: Stream> FusedFuture for Peek<'_, St>` [src]

#### `fn is_terminated(&self) -> bool` [src]

Returns `true` if the underlying future should no longer be polled.

### `impl<'a, St> Future for Peek<'a, St> where
St: Stream,` [src]

#### `type Output = Option<&'a St::Item>`

The type of value produced on completion.

#### `fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>` [src]

Attempt to resolve the future to a final value, registering the current task for wakeup if the value is not yet available. Read more

### `impl<'__pin, 'a, St: Stream> Unpin for Peek<'a, St> where
__Origin<'__pin, 'a, St>: Unpin,` [src]

## Auto Trait Implementations

### `impl<'a, St> RefUnwindSafe for Peek<'a, St> where
St: RefUnwindSafe,
<St as Stream>::Item: RefUnwindSafe,` [src]

### `impl<'a, St> Send for Peek<'a, St> where
St: Send,
<St as Stream>::Item: Send,` [src]

### `impl<'a, St> Sync for Peek<'a, St> where
St: Sync,
<St as Stream>::Item: Sync,` [src]

### `impl<'a, St> !UnwindSafe for Peek<'a, St>` [src]

## Blanket Implementations

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

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

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

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

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

Immutably borrows from an owned value. Read more

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

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

Mutably borrows from an owned value. Read more

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

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

Performs the conversion.

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

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

Performs the conversion.

### `impl<F> IntoFuture for F where
F: Future,` [src]

#### `type Output = <F as Future>::Output`

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

The output that the future will produce on completion.

#### `type Future = F`

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

Which kind of future are we turning this into?

#### `pub fn into_future(self) -> <F as IntoFuture>::Future` [src]

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

Creates a future from a value.

### `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.

#### `pub 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.

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

Performs the conversion.