From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Mon, 28 Mar 2022 17:47:58 +0000 (+0100)
Subject: W
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?a=commitdiff_plain;h=7dcd424a72dbfe053b89df533c48bf190f7b8f4a;p=rust-experiments.git

W
---

diff --git a/src/main.rs b/src/main.rs
index af3ef28..318d67e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,11 +1,12 @@
-trait Trait { }
-struct Struct;
-impl Trait for Struct { }
+use std::sync::mpsc;
 
-fn optmap(s: Option<&Struct>) -> Option<&dyn Trait> {
-    s.map(|s| s as _)
+async fn failure() {
+    let (_, rx) = mpsc::channel::<()>();
+    while let Ok(Some(thing)) = rx.try_recv() {
+    }
 }
 
+#[tokio::main]
 fn main() {
-    optmap(None);
+    failure().await;
 }