1 files changed, 55 insertions, 0 deletions
diff --git a/test/typeparam/issue49027.dir/a.go b/test/typeparam/issue49027.dir/a.go
new file mode 100644
index 0000000..da88297
--- /dev/null
+++ b/test/typeparam/issue49027.dir/a.go
@@ -0,0 +1,55 @@
+// 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 a
+
+func Conv(v interface{}) string {
+	return conv[string](v)
+}
+
+func conv[T any](v interface{}) T {
+	return v.(T)
+}
+
+func Conv2(v interface{}) (string, bool) {
+	return conv2[string](v)
+}
+
+func conv2[T any](v interface{}) (T, bool) {
+	x, ok := v.(T)
+	return x, ok
+}
+
+func Conv3(v interface{}) string {
+	return conv3[string](v)
+}
+
+func conv3[T any](v interface{}) T {
+	switch v := v.(type) {
+	case T:
+		return v
+	default:
+		var z T
+		return z
+	}
+}
+
+type Mystring string
+
+func (Mystring) Foo() {
+}
+
+func Conv4(v interface{Foo()}) Mystring {
+	return conv4[Mystring](v)
+}
+
+func conv4[T interface{Foo()}](v interface{Foo()}) T {
+	switch v := v.(type) {
+	case T:
+		return v
+	default:
+		var z T
+		return z
+	}
+}