--- /dev/null
+// errchk $G -e $F.go
+
+// Copyright 2009 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
+
+const (
+ // check that surrogate pair elements are invalid
+ // (d800-dbff, dc00-dfff).
+ _ = '\ud7ff' // ok
+ _ = '\ud800' // ERROR "Unicode"
+ _ = "\U0000D999" // ERROR "Unicode"
+ _ = '\udc01' // ERROR "Unicode"
+ _ = '\U0000dddd' // ERROR "Unicode"
+ _ = '\udfff' // ERROR "Unicode"
+ _ = '\ue000' // ok
+ _ = '\U0010ffff' // ok
+ _ = '\U00110000' // ERROR "Unicode"
+ _ = "abc\U0010ffffdef" // ok
+ _ = "abc\U00110000def" // ERROR "Unicode"
+ _ = '\Uffffffff' // ERROR "Unicode"
+)
+