1 files changed, 31 insertions, 0 deletions
diff --git a/test/typeparam/issue48838.go b/test/typeparam/issue48838.go
new file mode 100644
index 0000000..1711d04
--- /dev/null
+++ b/test/typeparam/issue48838.go
@@ -0,0 +1,31 @@
+// run
+
+// Copyright 2021 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.
+
+package main
+
+func main() {
+	check[string]()
+}
+
+func check[T any]() {
+	var result setter[T]
+	switch result.(type) {
+	case fooA[T]:
+	case fooB[T]:
+	}
+}
+
+type setter[T any] interface {
+	Set(T)
+}
+
+type fooA[T any] struct{}
+
+func (fooA[T]) Set(T) {}
+
+type fooB[T any] struct{}
+
+func (fooB[T]) Set(T) {}