From 2df3f490dd71e50fd074ade846397f4ac9cbb6f7 Mon Sep 17 00:00:00 2001
From: Yuki Okushi <jtitor@2k36.org>
Date: Wed, 5 Apr 2023 21:20:07 +0900
Subject: [PATCH] Add regression test for #80409

Signed-off-by: Yuki Okushi <jtitor@2k36.org>
---
 tests/ui/inference/issue-80409.rs | 36 +++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 tests/ui/inference/issue-80409.rs

diff --git a/tests/ui/inference/issue-80409.rs b/tests/ui/inference/issue-80409.rs
new file mode 100644
index 0000000000000..80cad6dfc46e4
--- /dev/null
+++ b/tests/ui/inference/issue-80409.rs
@@ -0,0 +1,36 @@
+// check-pass
+
+#![allow(unreachable_code, unused)]
+
+use std::marker::PhantomData;
+
+struct FsmBuilder<TFsm> {
+    _fsm: PhantomData<TFsm>,
+}
+
+impl<TFsm> FsmBuilder<TFsm> {
+    fn state(&mut self) -> FsmStateBuilder<TFsm> {
+        todo!()
+    }
+}
+
+struct FsmStateBuilder<TFsm> {
+    _state: PhantomData<TFsm>,
+}
+
+impl<TFsm> FsmStateBuilder<TFsm> {
+    fn on_entry<TAction: Fn(&mut StateContext<'_, TFsm>)>(&self, _action: TAction) {}
+}
+
+trait Fsm {
+    type Context;
+}
+
+struct StateContext<'a, TFsm: Fsm> {
+    context: &'a mut TFsm::Context,
+}
+
+fn main() {
+    let mut builder: FsmBuilder<usize> = todo!();
+    builder.state().on_entry(|_| {});
+}