I'm not disagreeing, but I am curious. Why is it cheaper? One less node allocated? (Oh, I think I see... PL_sv_undef gets reused instead of a new SV?)

This sounds like a job for those perl internals diagrams someone did at some point... Wish my memory was better.
--
Mike

In reply to Re: Re: Perl Idioms Explained - keys %{{map{$_=>1}@list}} by RMGir
in thread Perl Idioms Explained - keys %{{map{$_=>1}@list}} by broquaint

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