| // errorcheck | |
| // Copyright 2011 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 erroneous type switches are caught be the compiler. | |
| // Issue 2700, among other things. | |
| // Does not compile. | |
| package main | |
| import ( | |
| "io" | |
| ) | |
| type I interface { | |
| M() | |
| } | |
| func main(){ | |
| var x I | |
| switch x.(type) { | |
| case string: // ERROR "impossible" | |
| println("FAIL") | |
| } | |
| // Issue 2700: if the case type is an interface, nothing is impossible | |
| var r io.Reader | |
| _, _ = r.(io.Writer) | |
| switch r.(type) { | |
| case io.Writer: | |
| } | |
| // Issue 2827. | |
| switch _ := r.(type) { // ERROR "invalid variable name _|no new variables" | |
| } | |
| } | |