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