1 files changed, 40 insertions, 0 deletions
diff --git a/test/typeparam/issue47740.go b/test/typeparam/issue47740.go
new file mode 100644
index 0000000..f34394c
--- /dev/null
+++ b/test/typeparam/issue47740.go
@@ -0,0 +1,40 @@
+// 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
+
+import "fmt"
+
+type Exp[Ty any] interface {
+	Eval() Ty
+}
+
+// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
+// type Lit[Ty any] Ty
+//
+// func (lit Lit[Ty]) Eval() Ty       { return Ty(lit) }
+// func (lit Lit[Ty]) String() string { return fmt.Sprintf("(lit %v)", Ty(lit)) }
+
+type Eq[Ty any] struct {
+	a Exp[Ty]
+	b Exp[Ty]
+}
+
+func (e Eq[Ty]) String() string {
+	return fmt.Sprintf("(eq %v %v)", e.a, e.b)
+}
+
+// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
+// var (
+// 	e0 = Eq[int]{Lit[int](128), Lit[int](64)}
+// 	e1 = Eq[bool]{Lit[bool](true), Lit[bool](true)}
+// )
+
+func main() {
+	// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
+	// fmt.Printf("%v\n", e0)
+	// fmt.Printf("%v\n", e1)
+}