// the original sin: how wide is int xs[20][20]

::emit<
    ::decltype(
        ::extent<
            ::array<
                ::array<
                    ::remove_cv_t<
                        ::int32_t
                    >,
                    ::integral_constant<
                        ::size_t,
                        ::tuple_size<
                            ::array<
                                ::byte,
                                ::difference<'Z', 'F'>
                            >
                        >::value
                    >::value
                >,
                ::integral_constant<
                    ::size_t,
                    ::difference<'Z', 'F'>
                >::value
            >
        >::value
    )
>::commit;

// an array type says its extent, a bare type says its name
::emit<
    ::array<
        ::byte,
        ::difference<'Z', 'F'>
    >
>::commit;