Struct futures::future::Join4

#[must_use = "futures do nothing unless polled"]
pub struct Join4<A, B, C, D> where
    A: Future,
    B: Future<Error = <A as Future>::Error>,
    C: Future<Error = <A as Future>::Error>,
    D: Future<Error = <A as Future>::Error>,  { /* fields omitted */ }

Future for the join4 combinator, waiting for four futures to complete.

This is created by the Future::join4 method.

Trait Implementations

impl<A, B, C, D> Debug for Join4<A, B, C, D> where
    A: Future + Debug,
    B: Future<Error = <A as Future>::Error> + Debug,
    C: Future<Error = <A as Future>::Error> + Debug,
    D: Future<Error = <A as Future>::Error> + Debug,
    <A as Future>::Item: Debug,
    <B as Future>::Item: Debug,
    <C as Future>::Item: Debug,
    <D as Future>::Item: Debug, 

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

Formats the value using the given formatter.

impl<A, B, C, D> Future for Join4<A, B, C, D> where
    A: Future,
    B: Future<Error = <A as Future>::Error>,
    C: Future<Error = <A as Future>::Error>,
    D: Future<Error = <A as Future>::Error>, 

type Item = (<A as Future>::Item, <B as Future>::Item, <C as Future>::Item, <D as Future>::Item)

A successful value

type Error = <A as Future>::Error

An error

fn poll(
    &mut self,
    cx: &mut Context
) -> Result<Async<<Join4<A, B, C, D> as Future>::Item>, <Join4<A, B, C, D> as Future>::Error>

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