I wouldn't worry about my(0?$x:$y) too much.
Oh, I'm not "worried" -- there's no need to either deprecate or document it. I just think: (1) it is surprising that it parses at all, since I thought "my" took a list of variables; and (2) it shows the compile- and run-time effects of "my" in an interesting way.

In reply to Re^2: my (0?$a:$b): a koan by educated_foo
in thread my (0?$a:$b): a koan by educated_foo

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