Massive reduction of memory usage (down to one third).

t/serialize.t

@@ -0,0 +1,33 @@
+use Test::More;
+use strict;
+use warnings;
+
+plan tests => 2;
+
+BEGIN {
+    use FindBin;
+    use lib "$FindBin::Bin/../lib";
+}
+
+use Slic3r;
+use Slic3r::Geometry qw(scale);
+
+#==========================================================
+
+{
+    my $points = [
+        [226,701], [260,681], [109,420], [149,397], [300,658], [308,654],
+    ];
+    foreach my $point (@$points) {
+        @$point = map scale $_, @$point;
+    }
+    my $polyline = Slic3r::Polyline->new($points);
+    my $serialized = $polyline->serialize;
+    my $deserialized = $serialized->deserialize;
+    is scalar(@$deserialized), scalar(@$points), 'number of deserialized points';
+    is_deeply $deserialized, $points, 'deserialized points coordinates';
+}
+
+#==========================================================
+
+__END__