go source for verification 2026-05-22

test/typeparam/issue53477.go

@@ -0,0 +1,34 @@
+// run
+
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test that generic interface-interface comparisons resulting from
+// value switch statements are handled correctly.
+
+package main
+
+func main() {
+	f[X](0)
+}
+
+type Mer[T any] interface{ M(T) }
+type MNer[T any] interface {
+	Mer[T]
+	N()
+}
+
+type X int
+
+func (X) M(X) {}
+func (X) N()  {}
+
+func f[T MNer[T]](t T) {
+	switch Mer[T](t) {
+	case MNer[T](t):
+		// ok
+	default:
+		panic("FAIL")
+	}
+}