From 9e720cd48e2e02983c70b6d50f3412ea6b3b60c2 Mon Sep 17 00:00:00 2001
From: Wojciech Mazur <wmazur@virtuslab.com>
Date: Tue, 29 Jul 2025 09:18:53 +0200
Subject: [PATCH] Add regression test for #23616

---
 tests/pos/i23616.scala | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 tests/pos/i23616.scala

diff --git a/tests/pos/i23616.scala b/tests/pos/i23616.scala
new file mode 100644
index 000000000000..48f91d8cd77f
--- /dev/null
+++ b/tests/pos/i23616.scala
@@ -0,0 +1,22 @@
+trait Apply[F[_]]:
+  extension [A](fa: F[A])
+    def map[B](f: A => B): F[B]
+    def map2[B, Z](fb: F[B])(f: (A, B) => Z): F[Z] = ???
+
+  private case class IsMap[T <: Tuple](value: Tuple.Map[T, F])
+  private inline def tupledGeneric[T <: Tuple](tuple: Tuple.Map[T, F]): F[T] =
+    inline IsMap(tuple) match
+      case t: IsMap[h *: EmptyTuple] => t.value.head.map(_ *: EmptyTuple)
+      case t: IsMap[h *: t] =>
+        val head = t.value.head
+        val tail = tupledGeneric(t.value.tail)
+        head.map2(tail)(_ *: _)
+
+trait Monad[F[_]] extends Apply[F]:
+  extension [A](fa: F[A]) def flatMap[B](f: A => F[B]): F[B]
+  extension [A](fa: F[A]) override def map[B](f: A => B): F[B] = ???
+
+opaque type Kleisli[F[_], A, B] = A => F[B]
+given [F[_], A](using F: Monad[F]): Monad[[B] =>> Kleisli[F, A, B]] with
+  extension [B](k: Kleisli[F, A, B])
+    def flatMap[C](f: B => Kleisli[F, A, C]) = ???
\ No newline at end of file