rust - 有没有办法可以将 futures 0.1 转换为标准库 futures？

Question

async/await 功能即将推出，但仍有许多库仍在使用 futures 0.1。我们如何在两者之间进行转换？

Convert an async future to 0.1 future涵盖将异步 future 转换为 0.1 future 。

How do I erase the type of future in the new future API?谈论调用 0.1 future 并获得结果的 async 函数，但是我可以导入的 await!() 宏在哪里？它似乎不再编译。

struct A_future01;

impl A_future01 {
    pub fn exec1() -> Box<dyn Future<Item=String, Error=()>> {
        Box::new(futures::future::result("ok"))
    }

    pub fn exec2() -> Box<dyn Future<Item=String, Error=()>> {
        Box::new(call().unit_error().boxed().compat()) //Like this## Heading ##?
    }
}

async fn call() -> Result<(), Box<dyn std::error::Error>> {
    let result_from_a = A_future01::exec().await(); //how can I achieve this ?
    Ok(())
}

Answer 1

使用 Future01CompatExt 特性:

use futures01::future as future01;
use futures03::compat::Future01CompatExt;

fn make_future_01() -> impl future01::Future<Item = i32, Error = ()> {
    future01::ok(2)
}

async fn example_03_uses_01() -> Result<i32, ()> {
    let v = make_future_01().compat().await?;
    Ok(v)
}

[dependencies]
futures03 = { package = "futures", version = "0.3", features = ["compat"] }
futures01 = { package = "futures", version = "0.1" }