local acl = {}
do
	local acl = struct({
		meta = "B",
		id = "H"
	})

	local function acl_readstream(stream)
		local a = acl(stream:read(#acl))
		local perm = stream:read(a.meta & 0x3f)
		local 
	end

	function acl.read(stream, dperm, gid, uid)

	end

	function _acl:get_effective_perm(id, group, perm)

	end
end