http://www.perlmonks.org?node_id=801770


in reply to Re^2: Does @{ } copy arrays?
in thread Does @{ } copy arrays?

Interesting! That's the kind of answer I was hoping someone would post. For anyone who's keeping score, here's a benchmark and my results:

#!/usr/bin/perl use strict; use warnings; use Benchmark qw(cmpthese); my $i=0; cmpthese(-10, { deref => sub { my $aryptr = [qw(Once upon a time in a galaxy far far away +)]; if ( @{ $aryptr } ) { $i=1; } $aryptr = []; if ( @{ $aryptr } ) { $i=-1; } }, arylen => sub { my $aryptr = [qw(Once upon a time in a galaxy far far away +)]; if ( $#{ $aryptr } >= 0 ) { $i=1; } $aryptr = []; if ( $#{ $aryptr } >= 0 ) { $i=-1; } }, } ); __END__ Rate arylen deref arylen 95903/s -- -28% deref 132418/s 38% --

print pack("A25",pack("V*",map{1919242272+$_}(34481450,-49737472,6228,0,-285028276,6979,-1380265972)))