// 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: 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: i \(type I\) cannot have dynamic type X \(Foo method has pointer receiver\)"
}
}