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https://github.com/golang/go
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f1973f3164
Change-Id: Id21cdce35963dcdb96cc06252170590224c5aa17
GitHub-Last-Rev: 429dad0ceb
GitHub-Pull-Request: golang/go#28000
Reviewed-on: https://go-review.googlesource.com/c/139424
Reviewed-by: Ian Lance Taylor <iant@golang.org>
48 lines
968 B
Go
48 lines
968 B
Go
// errorcheck
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// Copyright 2009 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 various erroneous type switches are caught by the compiler.
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// Does not compile.
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package main
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import "io"
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func whatis(x interface{}) string {
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switch x.(type) {
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case int:
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return "int"
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case int: // ERROR "duplicate"
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return "int8"
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case io.Reader:
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return "Reader1"
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case io.Reader: // ERROR "duplicate"
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return "Reader2"
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case interface {
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r()
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w()
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}:
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return "rw"
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case interface { // ERROR "duplicate"
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w()
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r()
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}:
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return "wr"
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}
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return ""
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}
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func notused(x interface{}) {
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// The first t is in a different scope than the 2nd t; it cannot
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// be accessed (=> declared and not used error); but it is legal
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// to declare it.
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switch t := 0; t := x.(type) { // ERROR "declared and not used"
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case int:
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_ = t // this is using the t of "t := x.(type)"
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}
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}
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