1 use core::any::Any;
2 use core::pin::Pin;
3 use std::panic::{catch_unwind, AssertUnwindSafe, UnwindSafe};
4 
5 use futures_core::future::Future;
6 use futures_core::task::{Context, Poll};
7 use pin_project_lite::pin_project;
8 
9 pin_project! {
10     /// Future for the [`catch_unwind`](super::FutureExt::catch_unwind) method.
11     #[derive(Debug)]
12     #[must_use = "futures do nothing unless you `.await` or poll them"]
13     pub struct CatchUnwind<Fut> {
14         #[pin]
15         future: Fut,
16     }
17 }
18 
19 impl<Fut> CatchUnwind<Fut>
20 where
21     Fut: Future + UnwindSafe,
22 {
new(future: Fut) -> Self23     pub(super) fn new(future: Fut) -> Self {
24         Self { future }
25     }
26 }
27 
28 impl<Fut> Future for CatchUnwind<Fut>
29 where
30     Fut: Future + UnwindSafe,
31 {
32     type Output = Result<Fut::Output, Box<dyn Any + Send>>;
33 
poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>34     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
35         let f = self.project().future;
36         catch_unwind(AssertUnwindSafe(|| f.poll(cx)))?.map(Ok)
37     }
38 }
39