Function futures::future::poll_fn

Important traits for PollFn<F>

impl<T, F> Future for PollFn<F> where
    F: FnMut(&mut Context) -> Poll<T>,  type Output = T;

pub fn poll_fn<T, F>(f: F) -> PollFn<F> where
    F: FnMut(&mut Context) -> Poll<T>, 

Creates a new future wrapping around a function returning [Poll].

Polling the returned future delegates to the wrapped function.

Examples

#![feature(async_await, await_macro, futures_api)]
use futures::future::poll_fn;
use futures::task::{Context, Poll};

fn read_line(_cx: &mut Context<'_>) -> Poll<String> {
    Poll::Ready("Hello, World!".into())
}

let read_future = poll_fn(read_line);
assert_eq!(await!(read_future), "Hello, World!".to_owned());