Another point: the typeglob technique works only if @array is a global (package) variable:

 2:29 >perl -MData::Dump -wE "my @array = (10, 20); Double(*array); dd
+ @array; sub Double { local *copy = shift; for my $element (@copy) { 
+$element *= 2; } }"
Name "main::array" used only once: possible typo at -e line 1.
(10, 20)

 2:29 >
[download]

The following code, using a reference instead of a typeglob, performs the equivalent operation, but is more flexible, as @array may be either a global or a lexical:

 2:29 >perl -MData::Dump -wE "my @array = (10, 20); Double(\@array); d
+d @array; sub Double { my $array_ref = shift; for my $element (@$arra
+y_ref) { $element *= 2; } }"
(20, 40)

 2:30 >
[download]

Hope that helps,