is there any memory leak when using wax.struct

[dourgulf]

I wrote a test code like this:

function test() 
	local r = CGRect(1,1,2,2);
end
test();

and debug in createClosure method, wax_struct_userdata *structUserdata will allocate some memory. but the __gc breakpoint never reached.
is it a leak? or I had make a mistake?