mirror of
https://github.com/golang/go
synced 2024-11-23 18:30:06 -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>
48 lines
968 B
Go
48 lines
968 B
Go
// errorcheck
|
|
|
|
// 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.
|
|
|
|
// Verify that various erroneous type switches are caught by the compiler.
|
|
// Does not compile.
|
|
|
|
package main
|
|
|
|
import "io"
|
|
|
|
func whatis(x interface{}) string {
|
|
switch x.(type) {
|
|
case int:
|
|
return "int"
|
|
case int: // ERROR "duplicate"
|
|
return "int8"
|
|
case io.Reader:
|
|
return "Reader1"
|
|
case io.Reader: // ERROR "duplicate"
|
|
return "Reader2"
|
|
case interface {
|
|
r()
|
|
w()
|
|
}:
|
|
return "rw"
|
|
case interface { // ERROR "duplicate"
|
|
w()
|
|
r()
|
|
}:
|
|
return "wr"
|
|
|
|
}
|
|
return ""
|
|
}
|
|
|
|
func notused(x interface{}) {
|
|
// The first t is in a different scope than the 2nd t; it cannot
|
|
// be accessed (=> declared and not used error); but it is legal
|
|
// to declare it.
|
|
switch t := 0; t := x.(type) { // ERROR "declared and not used"
|
|
case int:
|
|
_ = t // this is using the t of "t := x.(type)"
|
|
}
|
|
}
|