impl_writeable_primitive!(u32, be32_to_array, 4, slice_to_be32);
impl_writeable_primitive!(u16, be16_to_array, 2, slice_to_be16);
impl_writeable_primitive!(u32, be32_to_array, 4, slice_to_be32);
impl_writeable_primitive!(u16, be16_to_array, 2, slice_to_be16);