1 files changed, 22 insertions, 0 deletions
diff --git a/test/typeparam/issue46591.go b/test/typeparam/issue46591.go
new file mode 100644
index 0000000000..e7b9fa2b48
--- /dev/null
+++ b/test/typeparam/issue46591.go
@@ -0,0 +1,22 @@
+// 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
+
+type T[_ any] struct{}
+
+var m = map[interface{}]int{
+	T[struct{ int }]{}: 0,
+	T[struct {
+		int "x"
+	}]{}: 0,
+}
+
+func main() {
+	if len(m) != 2 {
+		panic(len(m))
+	}
+}