Ok. The last one is best. 
my $only_one = 1 == ($x ? 1 : 0) + ($y ? 1 : 0) + ($z ? 1 :0);        
+    

my $only_one = 2 == (! $x) + (! $y) + (! $z);            

my $only_one = ($x || $y || $z) && (! ($x && $y)) && (! ($y && $z)) &&
+ (! ($z && $x));

my $only_one = (! ($x && $y && $z)) && ($x ^ $y ^ $z);

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

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