Struct bastion::message::Answer

pub struct Answer(_);

A Future returned when successfully "asking" a message using ChildRef::ask and which resolves to a Result<Msg, ()> where the Msg is the message answered by the child (see the msg! macro for more information).

Example

// The message that will be "asked"...
const ASK_MSG: &'static str = "A message containing data (ask).";
// The message the will be "answered"...
const ANSWER_MSG: &'static str = "A message containing data (answer).";

// Create a new child...
Bastion::children(|children| {
    children.with_exec(|ctx: BastionContext| {
        async move {
            // ...which will receive the message asked...
            msg! { ctx.recv().await?,
                msg: &'static str =!> {
                    assert_eq!(msg, ASK_MSG);
                    // Handle the message...

                    // ...and eventually answer to it...
                    answer!(ctx, ANSWER_MSG);
                };
                // This won't happen because this example
                // only "asks" a `&'static str`...
                _: _ => ();
            }

            Ok(())
        }
    })
}).expect("Couldn't create the children group.");

// Later, the message is "asked" to the child...
let answer: Answer = ctx.ask(&child_ref.addr(), ASK_MSG).expect("Couldn't send the message.");

// ...and the child's answer is received...
msg! { answer.await.expect("Couldn't receive the answer."),
    msg: &'static str => {
        assert_eq!(msg, ANSWER_MSG);
        // Handle the answer...
    };
    // This won't happen because this example
    // only answers a `&'static str`...
    _: _ => ();
}

Trait Implementations

impl Debug for Answer

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Future for Answer

type Output = Result<SignedMessage, ()>

The type of value produced on completion.

fn poll(self: Pin<&mut Self>, ctx: &mut Context) -> Poll<Self::Output>

Attempt to resolve the future to a final value, registering the current task for wakeup if the value is not yet available.