From 917f6bb389ce0e14ce3442af46018878839d5582 Mon Sep 17 00:00:00 2001
From: Tom Grigg <tomegrigg@gmail.com>
Date: Sun, 6 Jun 2021 11:34:47 -0700
Subject: [PATCH] Add regression test for #12723

---
 tests/pos/i12723.scala | 10 ++++++++++
 1 file changed, 10 insertions(+)
 create mode 100644 tests/pos/i12723.scala

diff --git a/tests/pos/i12723.scala b/tests/pos/i12723.scala
new file mode 100644
index 000000000000..d1cab3ede638
--- /dev/null
+++ b/tests/pos/i12723.scala
@@ -0,0 +1,10 @@
+class Fun[|*|[_, _]] {
+  enum ->[A, B] {
+    case BiId[X, Y]() extends ((X |*| Y) -> (X |*| Y))
+  }
+
+  def go[A, B](f: A -> B): Unit =
+    f match {
+      case ->.BiId() => ()
+    }
+}