From e8246730cbd6b85a7a8186a65cd3232273013453 Mon Sep 17 00:00:00 2001
From: Andrew Burkett <burkett.andrew@gmail.com>
Date: Fri, 17 Sep 2021 14:43:48 -0700
Subject: [PATCH] Fix Unusable Sink Implementation on scan

The current Sink implementation on stream::Scan requires the stream and
state types are the same which doesn't practically allow that
implementation to be used. This adds a separate generic to the Sink
implementation for state.
---
 futures-util/src/stream/stream/scan.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/futures-util/src/stream/stream/scan.rs b/futures-util/src/stream/stream/scan.rs
index c6ea456b33..c5cf035c55 100644
--- a/futures-util/src/stream/stream/scan.rs
+++ b/futures-util/src/stream/stream/scan.rs
@@ -115,11 +115,11 @@ where
 
 // Forwarding impl of Sink from the underlying stream
 #[cfg(feature = "sink")]
-impl<S, Fut, F, Item> Sink<Item> for Scan<S, S, Fut, F>
+impl<St, S, Fut, F, Item> Sink<Item> for Scan<St, S, Fut, F>
 where
-    S: Stream + Sink<Item>,
+    St: Stream + Sink<Item>,
 {
-    type Error = S::Error;
+    type Error = St::Error;
 
     delegate_sink!(stream, Item);
 }