Re: ffi.getmetatable
- From: Peter Colberg <peter@xxxxxxxxxxx>
- To: luajit@xxxxxxxxxxxxx
- Date: Wed, 26 Nov 2014 16:26:21 -0500
On Wed, Nov 26, 2014 at 11:51:07AM -0800, Ronan Collobert wrote:
> More generally when one hides something in the metatable (a global
> property of the “class” of a given object), right now one cannot
> retrieve it easily. Once in while, the case occurs, someone
> complains to me, and one has to play with the
> tonumber(ffi.typeof())+additional table trick.
Did you know this feature of ctypes?
local ffi = require("ffi")
local ctype = ffi.metatype("struct { int i; }", {
__index = {
class = "MyClass",
size = function(self)
return ffi.sizeof(self)
end,
}
})
assert(ctype.class == "MyClass")
assert(ctype:size() == 4)
local obj = ctype(123)
local objtype = ffi.typeof(obj)
assert(objtype.class == "MyClass")
assert(objtype:size() == 4)
That is the X to your Y :-).
Peter
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