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https://github.com/golang/go
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34b563f447
Fixes #10561. Provides a better diagnostic message for failed type switch satisfaction in the case that a value receiver is being used in place of the pointer receiver that implements and satisfies the interface. Change-Id: If8c13ba13f2a8d81bf44bac7c3a66c12921ba921 Reviewed-on: https://go-review.googlesource.com/35235 Reviewed-by: Matthew Dempsky <mdempsky@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
47 lines
1.1 KiB
Go
47 lines
1.1 KiB
Go
// errorcheck
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// Copyright 2016 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Check the compiler's switch handling that happens
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// at typechecking time.
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// This must be separate from other checks,
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// because errors during typechecking
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// prevent other errors from being discovered.
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package main
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// Verify that type switch statements with impossible cases are detected by the compiler.
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func f0(e error) {
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switch e.(type) {
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case int: // ERROR "impossible type switch case: e \(type error\) cannot have dynamic type int \(missing Error method\)"
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}
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}
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// Verify that the compiler rejects multiple default cases.
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func f1(e interface{}) {
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switch e {
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default:
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default: // ERROR "multiple defaults in switch"
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}
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switch e.(type) {
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default:
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default: // ERROR "multiple defaults in switch"
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}
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}
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type I interface {
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Foo()
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}
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type X int
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func (*X) Foo() {}
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func f2() {
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var i I
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switch i.(type) {
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case X: // ERROR "impossible type switch case: i \(type I\) cannot have dynamic type X \(Foo method has pointer receiver\)"
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}
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}
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