$ perl -MDevel::Size -e '@a = (0 .. 11); print Devel::Size::total_size(\@a)'
296

$ perl -MDevel::Size -e '@a = (0 .. 11); $i = $a[56788]; print Devel::Size::total_size(\@a)'
296

# Just to make sure perl doesn't optimize away the assignment
$ perl -MO=Deparse -MDevel::Size -e '@a = (0 .. 11); $i = $a[56788]; print Devel::Size::total_size(\@a)'
-e syntax OK
use Devel::Size;
@a = (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11);
$i = $a[56788];
print Devel::Size::total_size(\@a);

$ perl -v

This is perl, v5.8.0 built for MSWin32-x86-multi-thread
(with 1 registered patch, see perl -V for more detail)

Copyright 1987-2002, Larry Wall

Binary build 806 provided by ActiveState Corp. http://www.ActiveState.com
Built 00:45:44 Mar 31 2003

# snip the rest