Whenever you feel there's no intuitive way to do it, write a subroutine.

In this case, let's define, say, 

sub exactly_one { 1 == grep $_, @_; }

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Then you can do exactly_one($x, $y, $z) which is now cleaner than any other solution.

In reply to Re: One out of three ain't bad by ambrus
in thread One out of three ain't bad by saintmike

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