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e76d6a456b
Ensure that we have a test for when the compiler encounters a type switch on a non-interface value. Change-Id: Icb222f986894d0190e1241ca65396b4950e7d14f Reviewed-on: https://go-review.googlesource.com/38661 Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com> Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
57 lines
964 B
Go
57 lines
964 B
Go
// errorcheck
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// Copyright 2011 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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// Verify that erroneous type switches are caught be the compiler.
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// Issue 2700, among other things.
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// Does not compile.
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package main
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import (
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"io"
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)
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type I interface {
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M()
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}
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func main() {
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var x I
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switch x.(type) {
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case string: // ERROR "impossible"
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println("FAIL")
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}
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// Issue 2700: if the case type is an interface, nothing is impossible
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var r io.Reader
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_, _ = r.(io.Writer)
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switch r.(type) {
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case io.Writer:
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}
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// Issue 2827.
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switch _ := r.(type) { // ERROR "invalid variable name _|no new variables"
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}
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}
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func noninterface() {
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var i int
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switch i.(type) { // ERROR "cannot type switch on non-interface value"
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case string:
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case int:
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}
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type S struct {
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name string
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}
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var s S
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switch s.(type) { // ERROR "cannot type switch on non-interface value"
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}
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}
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