pub struct Permit<'a, T> { /* private fields */ }
Expand description

Permits to send one value into the channel.

Permit values are returned by Sender::reserve() and Sender::try_reserve() and are used to guarantee channel capacity before generating a message to send.

Implementations

Sends a value using the reserved capacity.

Capacity for the message has already been reserved. The message is sent to the receiver and the permit is consumed. The operation will succeed even if the receiver half has been closed. See Receiver::close for more details on performing a clean shutdown.

Examples
use tokio::sync::mpsc;

#[tokio::main]
async fn main() {
    let (tx, mut rx) = mpsc::channel(1);

    // Reserve capacity
    let permit = tx.reserve().await.unwrap();

    // Trying to send directly on the `tx` will fail due to no
    // available capacity.
    assert!(tx.try_send(123).is_err());

    // Send a message on the permit
    permit.send(456);

    // The value sent on the permit is received
    assert_eq!(rx.recv().await.unwrap(), 456);
}

Trait Implementations

Formats the value using the given formatter. Read more

Executes the destructor for this type. 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 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.