Client builder's executor setter is confusing for new tokio 0.2 alpha

[zimond]

Currently in hyper, the Builder::executor<E>() setter requires a for<'a> &'a E: tokio_executor::Executor bound. Which, in latest tokio (=0.2.0-alpha.4), only Sender meets this bound.

However, Sender is now not exported anymore by tokio. There seems to be no easy way to set custom executor.

[seanmonstar]

Yea, some impls could probably be added to Tokio... However, it seems like the tokio::Executor trait may go away. I've been thinking that instead hyper should just accept impl FnMut(Fut) -> Result<(), E> instead, so as to not need to depend on any external trait.

[sparky8251]

I'm currently facing this issue as well.

Code is

let runtime = tokio::runtime::Builder::new().build().unwrap();

let mut https = HttpsConnector::new().unwrap();
https.https_only(true);

let client = hyper::Client::builder()
    .executor(runtime.executor())
    .build::<_, hyper::Body>(https);

Anyone have a good way to work around this issue currently or am I stuck waiting for an official hyper/tokio fix?

[zimond]

@sparky8251 Currently you need to create a new executor, something like this (not tested):

struct DefaultExecutor(TaskExecutor);


impl Executor for DefaultExecutor {
    fn spawn(
        &mut self,
        future: Pin<Box<dyn Future<Output = ()> + Send>>
    ) -> Result<(), tokio_executor::SpawnError> {
        Ok(self.0.spawn(future))
    }

    fn status(&self) -> Result<(), tokio_executor::SpawnError> {
        self.0.status()
    }
}

impl Executor for &DefaultExecutor {
    fn spawn(
        &mut self,
        future: Pin<Box<dyn Future<Output = ()> + Send>>
    ) -> Result<(), tokio_executor::SpawnError> {
        Ok(self.0.spawn(future))
    }

    fn status(&self) -> Result<(), tokio_executor::SpawnError> {
        self.0.status()
    }
}

[danieleades]

futures::task::Spawn has landed.