File: typeswitch2.go

package info (click to toggle)
golang 2%3A1.2-2
  • links: PTS, VCS
  • area: main
  • in suites: jessie, stretch
  • size: 45,552 kB
  • ctags: 90,012
  • sloc: ansic: 168,396; asm: 15,852; yacc: 4,966; perl: 4,876; sh: 2,229; xml: 1,085; lisp: 947; python: 267; makefile: 243; awk: 106; cpp: 22
file content (47 lines) | stat: -rw-r--r-- 998 bytes parent folder | download | duplicates (35)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
// errorcheck

// Copyright 2009 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.

// Verify that various erroneous type switches are caught be the compiler.
// Does not compile.

package main

import "io"

func whatis(x interface{}) string {
	switch x.(type) {
	case int:
		return "int"
	case int: // ERROR "duplicate"
		return "int8"
	case io.Reader:
		return "Reader1"
	case io.Reader: // ERROR "duplicate"
		return "Reader2"
	case interface {
		r()
		w()
	}:
		return "rw"
	case interface {	// GCCGO_ERROR "duplicate"
		w()
		r()
	}: // GC_ERROR "duplicate"
		return "wr"

	}
	return ""
}

func notused(x interface{}) {
	// The first t is in a different scope than the 2nd t; it cannot
	// be accessed (=> declared and not used error); but it is legal
	// to declare it.
	switch t := 0; t := x.(type) { // ERROR "declared and not used"
	case int:
		_ = t // this is using the t of "t := x.(type)"
	}
}