private fun serialize_meta_string(type_name: String)
	do
		if plain_msgpack or not cache_metadata_strings then
			# String only version
			stream.write_msgpack_str type_name
			return
		end

		if cache.has_object(type_name) then
			# if already serialized, add reference
			var id = cache.id_for(type_name)
			stream.write_msgpack_ext(ext_typ_ref, id.to_bytes)
		else
			# serialize
			var id = cache.new_id_for(type_name)
			stream.write_msgpack_array 2 # obj+id, type_name
			stream.write_msgpack_ext(ext_typ_obj, id.to_bytes)
			stream.write_msgpack_str type_name
		end
	end