1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48

use core::future::Future;
use core::pin::Pin;
use core::task::{Context, Poll};

use implicit_await_macro::as_future_internal;

pub trait FutureAsFuture {
    fn as_future(self) -> Self;
}

impl<T: Future> FutureAsFuture for T {
    fn as_future(self) -> Self {
        self
    }
}

pub trait NonFutureAsFuture : Sized {
    fn as_future(self) -> Ready<Self>;
}

// Clone of future-rs' Ready, to avoid needing to take a dependency on them.
pub struct Ready<T>(Option<T>);

impl<T> Unpin for Ready<T> {}

impl<T> Future for Ready<T> {
    type Output = T;

    fn poll(mut self: Pin<&mut Self>, _context: &mut Context<'_>) -> Poll<Self::Output> {
        Poll::Ready(self.0.take().unwrap())
    }
}

pub fn ready<T>(t: T) -> Ready<T> {
    Ready(Some(t))
}

#[cfg(feature = "std")]
impl<T, E> NonFutureAsFuture for Result<T, E> {
    fn as_future(self) -> Ready<Self> {
        ready(self)
    }
}

include!{"as_future_core.rs"}

#[cfg(feature = "std")]
include!{"as_future_std.rs"}