Note that Perl does ship with a (still) core module called Class::Struct, which offers a simple syntax for OO programming.

An example I wrote 2 years ago is somewhat similar to the Point class example you provided. I only wrote it as a rebuttal to a claim that Perl OO programming is very hard without installing something from CPAN

package Planet;
use Class::Struct mass => '$', radius => '$';

use Math::Trig;

sub density {
    my $self = shift;
    my $vol = 4/3*pi*($self->radius)**3);
    return $vol/($self->mass);
}

package main;

use Planet;

my $Jupiter = Planet->new(mass => 1.8E27, radius => 6.9E7);

print "Jupiter has mass of " . $Jupiter->mass . " and ";
print "radius of " . $Jupiter->radius . "\n";
print "It's density is " . $Jupiter->density . "\n";
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Not as clean as your proposed syntax, but is something that can be used without needing anything from CPAN. And there are limitations, such as Class::Struct classes can only inherit from UNIVERSAL.

Edit: corrected syntax as pointed out by LanX. Also, changed mod:// links to doc://