From 2c5719a4321cbfa5b069d3f79e553d79596272af Mon Sep 17 00:00:00 2001
From: Tom Grigg <tomegrigg@gmail.com>
Date: Tue, 5 Jul 2022 11:35:28 -0700
Subject: [PATCH] Irrefutable for generators should not be filtering under
 `-source:future`

Fixes #15579
---
 compiler/src/dotty/tools/dotc/parsing/Parsers.scala |  2 +-
 tests/pos/i15579.scala                              | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)
 create mode 100644 tests/pos/i15579.scala

diff --git a/compiler/src/dotty/tools/dotc/parsing/Parsers.scala b/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
index e8ecf1c88f8c..dd019e21b049 100644
--- a/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
+++ b/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
@@ -2574,8 +2574,8 @@ object Parsers {
       atSpan(startOffset(pat), accept(LARROW)) {
         val checkMode =
           if casePat then GenCheckMode.FilterAlways
-          else if sourceVersion.isAtLeast(`3.2`) then GenCheckMode.CheckAndFilter
           else if sourceVersion.isAtLeast(`future`) then GenCheckMode.Check
+          else if sourceVersion.isAtLeast(`3.2`) then GenCheckMode.CheckAndFilter
           else GenCheckMode.FilterNow  // filter on source version < 3.2, for backward compat
         GenFrom(pat, subExpr(), checkMode)
       }
diff --git a/tests/pos/i15579.scala b/tests/pos/i15579.scala
new file mode 100644
index 000000000000..64b67cf3c069
--- /dev/null
+++ b/tests/pos/i15579.scala
@@ -0,0 +1,10 @@
+// scalac: -source:future
+
+trait Foo[A]:
+  def map[B](f: A => B): Foo[B] = ???
+
+def baz: Foo[(Int, String)] = ???
+
+@main def main =
+  for (x, y) <- baz
+  yield ()