Struct tokio::sync::watch::Receiver [−][src]
pub struct Receiver<T> { /* fields omitted */ }
sync
only.Expand description
Receives values from the associated Sender
.
Instances are created by the channel
function.
To turn this receiver into a Stream
, you can use the WatchStream
wrapper.
Implementations
impl<T> Receiver<T>
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impl<T> Receiver<T>
[src]pub fn borrow(&self) -> Ref<'_, T>
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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>
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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
Auto Trait Implementations
impl<T> !RefUnwindSafe for Receiver<T>
impl<T> Send for Receiver<T> where
T: Send + Sync,
T: Send + Sync,
impl<T> Sync for Receiver<T> where
T: Send + Sync,
T: Send + Sync,
impl<T> Unpin for Receiver<T>
impl<T> !UnwindSafe for Receiver<T>
Blanket Implementations
impl<T> BorrowMut<T> for T where
T: ?Sized,
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impl<T> BorrowMut<T> for T where
T: ?Sized,
[src]pub fn borrow_mut(&mut self) -> &mut T
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pub fn borrow_mut(&mut self) -> &mut T
[src]Mutably borrows from an owned value. Read more
impl<T> ToOwned for T where
T: Clone,
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impl<T> ToOwned for T where
T: Clone,
[src]type Owned = T
type Owned = T
The resulting type after obtaining ownership.
pub fn to_owned(&self) -> T
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pub fn to_owned(&self) -> T
[src]Creates owned data from borrowed data, usually by cloning. Read more
pub fn clone_into(&self, target: &mut T)
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pub 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