Struct tokio::sync::watch::Receiver[][src]

pub struct Receiver<T> { /* fields omitted */ }

Receives values from the associated Sender.

Instances are created by the channel function.

Implementations

impl<T> Receiver<T>[src]

pub fn borrow(&self) -> Ref<'_, T>[src]

Returns a reference to the most recently sent value

Outstanding borrows hold a read lock. This means that long lived borrows could cause the send half to block. It is recommended to keep the borrow as short lived as possible.

Examples

use tokio::sync::watch;

let (_, rx) = watch::channel("hello");
assert_eq!(*rx.borrow(), "hello");

pub async fn changed(&mut self) -> Result<(), RecvError>[src]

Wait for a change notification

Returns when a new value has been sent by the Sender since the last time changed() was called. When the Sender half is dropped, Err is returned.

Examples

use tokio::sync::watch;

#[tokio::main]
async fn main() {
    let (tx, mut rx) = watch::channel("hello");

    tokio::spawn(async move {
        tx.send("goodbye").unwrap();
    });

    assert!(rx.changed().await.is_ok());
    assert_eq!(*rx.borrow(), "goodbye");

    // The `tx` handle has been dropped
    assert!(rx.changed().await.is_err());
}

Trait Implementations

impl<T> Clone for Receiver<T>[src]

impl<T: Debug> Debug for Receiver<T>[src]

impl<T> Drop for Receiver<T>[src]

Auto Trait Implementations

impl<T> !RefUnwindSafe for Receiver<T>

impl<T> Send for Receiver<T> where
    T: Send + Sync

impl<T> Sync for Receiver<T> where
    T: Send + Sync

impl<T> Unpin for Receiver<T>

impl<T> !UnwindSafe for Receiver<T>

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized
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impl<T> Borrow<T> for T where
    T: ?Sized
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impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

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

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

impl<T> ToOwned for T where
    T: Clone
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type Owned = T

The resulting type after obtaining ownership.

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.

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.