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https://github.com/golang/go
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f9dcda3fd8
Change-Id: I98751d0b2d8aefcf537b6d5200d0b52ffacf1105 Reviewed-on: https://go-review.googlesource.com/c/go/+/363439 Trust: Robert Griesemer <gri@golang.org> Run-TryBot: Robert Griesemer <gri@golang.org> Reviewed-by: Robert Findley <rfindley@google.com>
57 lines
999 B
Go
57 lines
999 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 by 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|not an interface"
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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|not an interface"
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}
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}
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