MooseX::Clone::Meta::Attribute::Trait::Copy (3pm)

    has foo => (
        isa => "ArrayRef",
        traits => [qw(Copy)],
    );

Unlike the \*(C`Clone\*(C' trait, which does deep copying of almost anything, this trait will only do one additional level of copying of arrays and hashes.

This is both simpler and faster when you don't need a real deep copy of the entire structure, and probably more correct.