Struct SelectedOperation

pub struct SelectedOperation<'a> { /* private fields */ }

A selected operation that needs to be completed.

To complete the operation, call send or recv.

Panics

Forgetting to complete the operation is an error and might lead to deadlocks. If a SelectedOperation is dropped without completion, a panic occurs.

Implementations

impl SelectedOperation<'_>

pub fn index(&self) -> usize

Returns the index of the selected operation.

Examples

use crossbeam_channel::{bounded, Select};

let (s1, r1) = bounded::<()>(0);
let (s2, r2) = bounded::<()>(0);
let (s3, r3) = bounded::<()>(1);

let mut sel = Select::new();
let oper1 = sel.send(&s1);
let oper2 = sel.recv(&r2);
let oper3 = sel.send(&s3);

// Only the last operation is ready.
let oper = sel.select();
assert_eq!(oper.index(), 2);
assert_eq!(oper.index(), oper3);

// Complete the operation.
oper.send(&s3, ()).unwrap();

pub fn send<T>(self, s: &Sender<T>, msg: T) -> Result<(), SendError<T>>

Completes the send operation.

The passed Sender reference must be the same one that was used in Select::send when the operation was added.

Panics

Panics if an incorrect Sender reference is passed.

Examples

use crossbeam_channel::{bounded, Select, SendError};

let (s, r) = bounded::<i32>(0);
drop(r);

let mut sel = Select::new();
let oper1 = sel.send(&s);

let oper = sel.select();
assert_eq!(oper.index(), oper1);
assert_eq!(oper.send(&s, 10), Err(SendError(10)));

pub fn recv<T>(self, r: &Receiver<T>) -> Result<T, RecvError>

Completes the receive operation.

The passed Receiver reference must be the same one that was used in Select::recv when the operation was added.

Panics

Panics if an incorrect Receiver reference is passed.

Examples

use crossbeam_channel::{bounded, Select, RecvError};

let (s, r) = bounded::<i32>(0);
drop(s);

let mut sel = Select::new();
let oper1 = sel.recv(&r);

let oper = sel.select();
assert_eq!(oper.index(), oper1);
assert_eq!(oper.recv(&r), Err(RecvError));

Trait Implementations

impl Debug for SelectedOperation<'_>

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Drop for SelectedOperation<'_>

fn drop(&mut self)

Executes the destructor for this type.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 88 bytes