Of course, we should really throw in a truly "plain perl" example as well:

C:\test>type junk99.pl
use Benchmark qw(cmpthese);

{
    package Foo1;
    sub new { bless $_[1], $_[0] }
    sub foo { $_[0]{foo} }
}

{
    package Foo2;
    use Moo;
    has foo => (is => 'ro');
}

{
    package Foo3;
    use Moose;
    has foo => (is => 'ro');
}

our $foo1 = Foo1::->new({foo => 0});
our $foo2 = Foo2::->new({foo => 0});
our $foo3 = Foo3::->new({foo => 0});
our $foo4 = { foo => 0 };

cmpthese( -3, {
    OO_perl     => q[ $foo1->foo for 1 .. 1000; ],
    moo         => q[ $foo2->foo for 1 .. 1000; ],
    moose       => q[ $foo3->foo for 1 .. 1000; ],
    plain_perl  => q[ $foo4->{foo} for 1 .. 1000; ],
});
C:\test>junk99
             Rate      moose        moo    OO_perl plain_perl
moose      2004/s         --        -3%       -15%       -74%
moo        2068/s         3%         --       -13%       -73%
OO_perl    2366/s        18%        14%         --       -69%
plain_perl 7624/s       280%       269%       222%         --
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