pub struct WeakSender<T> { /* private fields */ }
Expand description

A sender that does not prevent the channel from being closed.

If all Sender instances of a channel were dropped and only WeakSender instances remain, the channel is closed.

In order to send messages, the WeakSender needs to be upgraded using WeakSender::upgrade, which returns Option<Sender>. It returns None if all Senders have been dropped, and otherwise it returns a Sender.

#Examples

use tokio::sync::mpsc::channel;

#[tokio::main]
async fn main() {
    let (tx, _rx) = channel::<i32>(15);
    let tx_weak = tx.downgrade();
   
    // Upgrading will succeed because `tx` still exists.
    assert!(tx_weak.upgrade().is_some());
   
    // If we drop `tx`, then it will fail.
    drop(tx);
    assert!(tx_weak.clone().upgrade().is_none());
}

Implementations

Tries to convert a WeakSender into a Sender. This will return Some if there are other Sender instances alive and the channel wasn’t previously dropped, otherwise None is returned.

Trait Implementations

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.