From d52b3656e4caca7591d5e5223caf9055bc57780f Mon Sep 17 00:00:00 2001
From: Olivier Blanvillain <olivier.blanvillain@gmail.com>
Date: Fri, 11 Jun 2021 11:32:03 +0200
Subject: [PATCH] Add test case

---
 tests/neg/12549.scala | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 tests/neg/12549.scala

diff --git a/tests/neg/12549.scala b/tests/neg/12549.scala
new file mode 100644
index 000000000000..4e2a5531efa0
--- /dev/null
+++ b/tests/neg/12549.scala
@@ -0,0 +1,18 @@
+enum Bool {
+  case True
+  case False
+}
+
+import Bool.*
+
+type Not[B <: Bool] = B match {
+  case True.type => False.type
+  case False.type => True.type
+  case _ => "unreachable"
+}
+
+def foo[B <: Bool & Singleton]: Unit = {
+  implicitly[Not[B] =:= "unreachable"] // error
+
+  ()
+}