Russ Cox | 4bdf1fc | 2011-09-26 19:35:21 -0400 | [diff] [blame] | 1 | // $G $D/$F.go && $L $F.$A && ./$A.out |
Ian Lance Taylor | 22a6747 | 2008-10-24 22:40:32 -0700 | [diff] [blame] | 2 | |
| 3 | // Copyright 2009 The Go Authors. All rights reserved. |
| 4 | // Use of this source code is governed by a BSD-style |
| 5 | // license that can be found in the LICENSE file. |
| 6 | |
| 7 | package main |
Rob Pike | 325cf8e | 2010-03-24 16:46:53 -0700 | [diff] [blame] | 8 | |
| 9 | type I interface{} |
| 10 | |
| 11 | func foo1(i int) int { return i } |
Ian Lance Taylor | 22a6747 | 2008-10-24 22:40:32 -0700 | [diff] [blame] | 12 | func foo2(i int32) int32 { return i } |
| 13 | func main() { |
Rob Pike | 325cf8e | 2010-03-24 16:46:53 -0700 | [diff] [blame] | 14 | var i I |
| 15 | i = 1 |
| 16 | var v1 = i.(int) |
| 17 | if foo1(v1) != 1 { |
| 18 | panic(1) |
| 19 | } |
| 20 | var v2 = int32(i.(int)) |
| 21 | if foo2(v2) != 1 { |
| 22 | panic(2) |
| 23 | } |
Russ Cox | 4bdf1fc | 2011-09-26 19:35:21 -0400 | [diff] [blame] | 24 | |
| 25 | shouldPanic(p1) |
| 26 | } |
| 27 | |
| 28 | func p1() { |
| 29 | var i I |
| 30 | i = 1 |
Rob Pike | 325cf8e | 2010-03-24 16:46:53 -0700 | [diff] [blame] | 31 | var v3 = i.(int32) // This type conversion should fail at runtime. |
| 32 | if foo2(v3) != 1 { |
| 33 | panic(3) |
| 34 | } |
Ian Lance Taylor | 22a6747 | 2008-10-24 22:40:32 -0700 | [diff] [blame] | 35 | } |
Russ Cox | 4bdf1fc | 2011-09-26 19:35:21 -0400 | [diff] [blame] | 36 | |
| 37 | func shouldPanic(f func()) { |
| 38 | defer func() { |
| 39 | if recover() == nil { |
| 40 | panic("function should panic") |
| 41 | } |
| 42 | }() |
| 43 | f() |
| 44 | } |