mirror of
https://github.com/golang/go
synced 2024-11-05 18:26:10 -07:00
f1973f3164
Change-Id: Id21cdce35963dcdb96cc06252170590224c5aa17
GitHub-Last-Rev: 429dad0ceb
GitHub-Pull-Request: golang/go#28000
Reviewed-on: https://go-review.googlesource.com/c/139424
Reviewed-by: Ian Lance Taylor <iant@golang.org>
57 lines
964 B
Go
57 lines
964 B
Go
// 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 by 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"
|
|
}
|
|
}
|
|
|
|
func noninterface() {
|
|
var i int
|
|
switch i.(type) { // ERROR "cannot type switch on non-interface value"
|
|
case string:
|
|
case int:
|
|
}
|
|
|
|
type S struct {
|
|
name string
|
|
}
|
|
var s S
|
|
switch s.(type) { // ERROR "cannot type switch on non-interface value"
|
|
}
|
|
}
|