1 files changed, 46 insertions, 0 deletions
diff --git a/test/typeparam/stringable.go b/test/typeparam/stringable.go
new file mode 100644
index 0000000000..9340a3b10a
--- /dev/null
+++ b/test/typeparam/stringable.go
@@ -0,0 +1,46 @@
+// run -gcflags=-G=3
+
+// 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
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+type Stringer interface {
+	String() string
+}
+
+// stringableList is a slice of some type, where the type
+// must have a String method.
+type stringableList[T Stringer] []T
+
+func (s stringableList[T]) String() string {
+	var sb strings.Builder
+	for i, v := range s {
+		if i > 0 {
+			sb.WriteString(", ")
+		}
+		sb.WriteString(v.String())
+	}
+	return sb.String()
+}
+
+type myint int
+
+func (a myint) String() string {
+	return strconv.Itoa(int(a))
+}
+
+func main() {
+	v := stringableList[myint]{ myint(1), myint(2) }
+
+	if got, want := v.String(), "1, 2"; got != want {
+                panic(fmt.Sprintf("got %s, want %s", got, want))
+	}
+}