DB<173> use Time::HiRes qw/time/

  DB<174> @x=();$t=time; for (my $i=$start; $i<=$end;$i++) { push @x, $a[$i]}; print time-$t
0.21531081199646

  DB<175> @y=(); $t=time; push @y, $_ for @a[$start..$end]; print time-$t
0.1353440284729

  DB<176> @z=();$t=time; push @z, $a[$_] for $start..$end; print time-$t 
0.142512083053589

##</code><code>##

  DB<180> %h=(); $i=$start; $t=time; push @$_, $i++ for @h{@a[$start..$end]}; print time-$t
 => 1
0.427901983261108