From a945ce09960a55a6ac657a2a7aa3d72f8e00344e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ch=E1=BA=BF=20V=C5=A9=20Gia=20Hy?= <cvghy116@gmail.com>
Date: Wed, 5 May 2021 16:15:42 +0700
Subject: [PATCH] stream: implement Error and Display for
 BroadcastStreamRecvError (#3745)

---
 tokio-stream/src/wrappers/broadcast.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tokio-stream/src/wrappers/broadcast.rs b/tokio-stream/src/wrappers/broadcast.rs
index 06a982d17..3bddbb741 100644
--- a/tokio-stream/src/wrappers/broadcast.rs
+++ b/tokio-stream/src/wrappers/broadcast.rs
@@ -27,6 +27,16 @@ pub enum BroadcastStreamRecvError {
     Lagged(u64),
 }
 
+impl fmt::Display for BroadcastStreamRecvError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            BroadcastStreamRecvError::Lagged(amt) => write!(f, "channel lagged by {}", amt),
+        }
+    }
+}
+
+impl std::error::Error for BroadcastStreamRecvError {}
+
 async fn make_future<T: Clone>(mut rx: Receiver<T>) -> (Result<T, RecvError>, Receiver<T>) {
     let result = rx.recv().await;
     (result, rx)