scala - 不能将 futures-util crate 与 Actix 一起使用，因为特征 Future 未实现

Question

<分区>

Answer 1

在您的项目中，您使用futures-util 中包含的futures 的join_all 函数。看起来这个 crate 与 futures 的 actix 版本有冲突。

在actix 0.7.10

futures = "0.1"

在futures-util 0.2.1 :

futures = "~0.1.15"

我建议你直接使用 futures 中的 join_all:

[package]
name = "Battlefield Vietnam"
version = "0.0.1"

[dependencies]
actix = "0.7"
futures = "0.1"
tokio = "0.1.7"

extern crate actix;
extern crate futures;
extern crate tokio;

use actix::prelude::*;
use futures::future::*;
use futures::Future;
use std::time::SystemTime;

/// Define `Ping` message
struct Ping(usize);

impl Message for Ping {
    type Result = usize;
}

/// Actor
struct MyActor {
    count: usize,
}

/// Declare actor and its context
impl Actor for MyActor {
    type Context = Context<Self>;
}

/// Handler for `Ping` message
impl Handler<Ping> for MyActor {
    type Result = usize;

    fn handle(&mut self, msg: Ping, _: &mut Context<Self>) -> Self::Result {
        self.count += msg.0;
        self.count
    }
}

fn main() {
    // start system, this is required step
    System::run(|| {
        // start new actor
        let addr = MyActor { count: 10 }.start();

        let start = SystemTime::now();

        // send message and get future for result
        let res = join_all((1..10).into_iter().map(move |x| addr.send(Ping(x))));

        // handle() returns tokio handle
        tokio::spawn(
            res.map(move |res| {
                let difference = start
                    .duration_since(start)
                    .expect("SystemTime::duration_since failed");
                println!("Time taken: {:?}", difference);

                // stop system and exit
                System::current().stop();
            })
            .map_err(|_| ()),
        );
    });
}