gistfile1.txt

has foo => (
    is      => 'ro',
    lazy    => 1,
    default => sub { $_[0]->_foo_bar->[0] },
);

has bar => (
    is      => 'ro',
    lazy    => 1,
    default => sub { $_[0]->_foo_bar->[1] },
);

has _foobar => (
    is      => 'ro',
    lazy    => 1,
    default => sub { ...; return [ $foo, $bar ] },
);