| // errorcheck | 
 |  | 
 | // Copyright 2016 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. | 
 |  | 
 | // Verify that type switch statements with duplicate cases are detected | 
 | // by the compiler. | 
 | // Does not compile. | 
 |  | 
 | package main | 
 |  | 
 | import "fmt" | 
 |  | 
 | func f4(e interface{}) { | 
 | 	switch e.(type) { | 
 | 	case int: | 
 | 	case int: // ERROR "duplicate case int in type switch" | 
 | 	case int64: | 
 | 	case error: | 
 | 	case error: // ERROR "duplicate case error in type switch" | 
 | 	case fmt.Stringer: | 
 | 	case fmt.Stringer: // ERROR "duplicate case fmt.Stringer in type switch" | 
 | 	case struct { | 
 | 		i int "tag1" | 
 | 	}: | 
 | 	case struct { | 
 | 		i int "tag2" | 
 | 	}: | 
 | 	case struct { // ERROR "duplicate case struct { i int .tag1. } in type switch" | 
 | 		i int "tag1" | 
 | 	}: | 
 | 	} | 
 | } | 
 |  |