From b82e1c2cb156491728f4c23fa8e97b2c72ea9e1f Mon Sep 17 00:00:00 2001
From: odersky <odersky@gmail.com>
Date: Thu, 10 Nov 2022 19:03:16 +0100
Subject: [PATCH 1/2] Test case

Closes #16311
---
 tests/pos/i16311.scala | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 tests/pos/i16311.scala

diff --git a/tests/pos/i16311.scala b/tests/pos/i16311.scala
new file mode 100644
index 000000000000..d3e110860545
--- /dev/null
+++ b/tests/pos/i16311.scala
@@ -0,0 +1,17 @@
+trait Tagged[U]
+type WithTag[+T, U] = T & Tagged[U]
+
+trait FromInput[Val]
+implicit def coercedScalaInput[T]: FromInput[WithTag[T, Int]] = ???
+implicit def optionInput[T](implicit ev: FromInput[T]): FromInput[Option[T]] = ???
+
+trait WithoutInputTypeTags[T]
+implicit def coercedOptArgTpe[T]: WithoutInputTypeTags[Option[WithTag[T, Int]]] = ???
+
+trait InputType[+T]
+class OptionInputType[T](ofType: InputType[T]) extends InputType[Option[T]]
+
+type Argument[T]
+def argument[T](argumentType: InputType[T])(implicit fromInput: FromInput[T], res: WithoutInputTypeTags[T]): Argument[Option[T]] = ???
+
+def test = argument(OptionInputType(??? : InputType[WithTag[Boolean, Int]]))

From 3c883768d41683cb2d9a7bddf3628e1e4b0e1bfd Mon Sep 17 00:00:00 2001
From: odersky <odersky@gmail.com>
Date: Thu, 10 Nov 2022 20:35:31 +0100
Subject: [PATCH 2/2] Move test to proper place

need to allow deep subtype checking
---
 tests/{pos => pos-deep-subtype}/i16311.scala | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename tests/{pos => pos-deep-subtype}/i16311.scala (100%)

diff --git a/tests/pos/i16311.scala b/tests/pos-deep-subtype/i16311.scala
similarity index 100%
rename from tests/pos/i16311.scala
rename to tests/pos-deep-subtype/i16311.scala