Struct tokio::sync::watch::Receiver [−][src]
pub struct Receiver<T> { /* fields omitted */ }
This is supported on crate feature
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
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");
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> !UnwindSafe for Receiver<T>
Blanket Implementations
Mutably borrows from an owned value. Read more