3 // Copyright 2009 The Go Authors. All rights reserved.
4 // Use of this source code is governed by a BSD-style
5 // license that can be found in the LICENSE file.
7 // Verify that various erroneous type switches are caught by the compiler.
14 func whatis(x interface{}) string {
18 case int: // ERROR "duplicate"
22 case io.Reader: // ERROR "duplicate"
29 case interface { // ERROR "duplicate"