| // $G $D/$F.go && $L $F.$A && ./$A.out |
| |
| // 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. |
| |
| package main |
| |
| import "unsafe" |
| |
| func use(bool) { } |
| |
| func stringptr(s string) uintptr { |
| return *(*uintptr)(unsafe.Pointer(&s)); |
| } |
| |
| func isfalse(b bool) { |
| if b { panicln("wanted false, got true") } // stack will explain where |
| } |
| |
| func istrue(b bool) { |
| if !b { panicln("wanted true, got false") } // stack will explain where |
| } |
| |
| func main() { |
| var a []int; |
| var b map[string]int; |
| |
| var c string = "hello"; |
| var d string = "hel"; // try to get different pointer |
| d = d + "lo"; |
| if stringptr(c) == stringptr(d) { |
| panic("compiler too smart -- got same string") |
| } |
| |
| var e = make(chan int); |
| |
| var ia interface{} = a; |
| var ib interface{} = b; |
| var ic interface{} = c; |
| var id interface{} = d; |
| var ie interface{} = e; |
| |
| // these comparisons are okay because |
| // string compare is okay and the others |
| // are comparisons where the types differ. |
| isfalse(ia == ib); |
| isfalse(ia == ic); |
| isfalse(ia == id); |
| isfalse(ib == ic); |
| isfalse(ib == id); |
| istrue(ic == id); |
| istrue(ie == ie); |
| |
| // 6g used to let this go through as true. |
| var g uint64 = 123; |
| var h int64 = 123; |
| var ig interface{} = g; |
| var ih interface{} = h; |
| isfalse(ig == ih); |
| |
| // map of interface should use == on interface values, |
| // not memory. |
| // TODO: should m[c], m[d] be valid here? |
| var m = make(map[interface{}] int); |
| m[ic] = 1; |
| m[id] = 2; |
| if m[ic] != 2 { |
| panic("m[ic] = ", m[ic]); |
| } |
| } |
| |