<=> and obfuscation

[Bill Stewart HO 4K-435 x0705]

People have been arguing about the statement that
	b ^= a ^= b ^= a;
gives 0 when a and b are the same.  However, you've misunderstood the original
statement - the problem is not when a and b have the same VALUE, but when they
have the same ADDRESS.  Yes, it works fine when a and b are different variables
with the same value.  However, in a subroutine you might get two variables with
the same address.  Then the statement is equivalent to

	a ^= a ^= a ^= a

Well, a^=a becomes zero, gets ^ed with a, which is now 0m and gets ^ed with 0
again, still giving 0.
-- 
Bill Stewart	ho95c!wcs AT&T Bell Labs, Holmdel NJ
HO 4K-435 x0705   (201-949-0705)
{allegra, ucbvax!ihnp4, decvax!harpo}!houxf!stewart
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Sorry if the articles I'm replying to re ancient; we lost news for a month.