From f7d6b8994c3998feffdc51560a51d29009772d71 Mon Sep 17 00:00:00 2001
From: Mike Foster <i.am.mike.foster@gmail.com>
Date: Tue, 2 Jun 2026 13:23:11 +0000
Subject: [PATCH] check reverse inference of closure return type for zip_with

---
 crates/try_v2/src/transform.rs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/crates/try_v2/src/transform.rs b/crates/try_v2/src/transform.rs
index ddaa29c..8f31945 100644
--- a/crates/try_v2/src/transform.rs
+++ b/crates/try_v2/src/transform.rs
@@ -319,5 +319,14 @@ mod tests {
             let custom = Transform::zip_with(some_1, some_2, |x, y| x + i32::from(y));
             assert_eq!(stdlib, custom);
         }
+
+        #[test]
+        // https://rust-lang.zulipchat.com/#narrow/channel/605325-t-lang.2Ftry/topic/Type.20inference.20is.20one-way/near/599375356
+        fn reverse_infer() {
+            let some_1 = Some(-1_i32);
+            let some_2 = Some(2_u16);
+            let custom: Option<()> = Transform::zip_with(some_1, some_2, |_, _| Default::default());
+            assert_eq!(custom, Some(()));
+        }
     }
 }