sub foo {
    my $m = shift;
    my @array = ($m*1, $m*2, $m*3);
    return \@array;
}
my $x = foo(2);
my $y = foo(3);

use Data::Dump;
dd $x;  # [2, 4, 6]
dd $y;  # [3, 6, 9]

$x = undef;  # *now* the memory for that array is freed