🚀 go-pugleaf

In article <3vtat5INNovr@hubble.asymetrix.com>,
Michael Taylor <michaelt@asymetrix.com> wrote:
>fenster@shadow.cs.columbia.edu (Sam Fenster) wrote:
>>a2675528@athena.rrz.Uni-Koeln.DE (Paul Sponagl) writes:
>>> 		a ^=b; b^=a;a ^=b;
>>This sets `a' and `b' to zero if they refer to the same object.
>
>Wrong!
>
>Let a = 1001110
>and b = 1001110
>
>a ^= b; // -> a = 0
>b ^= a; // -> b = 1001110
>a ^= b; // -> a = 1001110

No.  If a and be are the same object then you'll get

a ^= a	// (a = 0);
a ^= a	// (a = 0);
a ^= a	// (a = 0);

Which is incorrect!

Notice he didn't say same value, he said same object.

It also doesn't work if ^= isn't defined on the type.

Warner


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