golang switch6 代码
文件路径：/test/switch6.go
/ 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.
/ Check the compiler's switch handling that happens
/ at typechecking time.
/ This must be separate from other checks,
/ because errors during typechecking
/ prevent other errors from being discovered.
package main
/ Verify that type switch statements with impossible cases are detected by the compiler.
func f0(e error) {
switch e.(type) {
case int: / ERROR "impossible type switch case: (int\n\t)?e \(.*type error\) cannot have dynamic type int \(missing Error method\)"
}
}
/ Verify that the compiler rejects multiple default cases.
func f1(e interface{}) {
switch e {
default:
default: / ERROR "multiple defaults( in switch)?"
}
switch e.(type) {
default:
default: / ERROR "multiple defaults( in switch)?"
}
}
type I interface {
Foo()
}
type X int
func (*X) Foo() {}
func f2() {
var i I
switch i.(type) {
case X: / ERROR "impossible type switch case: (X\n\t)?i \(.*type I\) cannot have dynamic type X \(Foo method has pointer receiver\)"
}
}