Luajit cdata with metatables....

[Daurnimator <quae@...>]

(sorry, this question was sent to old list address; and was meant to
be posted before my follow up question: "luajit FFI cdata problem")

Hi List,

I had a search of the list archives and nothing came up on the topic...

I would like to attach metamethods to some luajit2 ffi cdata
objects... Whats the best way to go about this?

eg:
local foo = ffi.new("int[3]",5,6,7)
local t = { [0]=x , y , z }
setmetatable(foo,{__index=function(ob,key) return ob[t[key]] end })

First thought to come to mind is newproxy... but luajit probably has a
smarter/better way?

Daurn.

Addendum:
I was trying to use 2 tables as a back and forth conversion of cdata
and userdata; but cdata as keys in a table seems to be a bad idea.
local edge_methods = {} -- methods to support.

local tocdata = setmetatable ( { } , { __mode = "k" } )
local touserdata
	touserdata = setmetatable ( { } , {
			__mode = "kv" ;
			__index = function ( t , cdata )
				local v = newproxy ( true )
				getmetatable ( v ).__index = function ( udata , k )
					local method = edge_methods [ k ]
					if method then
						return method
					else
						local cdata = tocdata [ udata ] [ k ]
						local udata = touserdata [ cdata ]
						return udata
					end
				end
				getmetatable ( v ).__newindex = function ( udata , k , v )
					tocdata [ udata ] [ k ] = v
				end
				getmetatable ( v ).__tostring = function ( udata )
					return "Dart" .. tostring ( tocdata [ udata ] ):match("cdata(<.*>)")
				end

				tocdata [ v ] = cdata
				rawset ( t , cdata , v )
				return v
			end ;
		} )