protect a set in c (non-existing elements)

[Thijs Schreijer <thijs@...>]

Hi list,

In Lua I would simply protect a set with something like this;

function protect(self)
  return setmetatable(self, {
    __index = function(self, key)
      return rawget(self,key) or error("Key '"..tostring(key).."' not found.",2)
    end})
end

local set = protect({ a = 1 , b = 2 })

print(set.a)
print(set.b)
print(set.c)  --> error

I have a c module, for which I want to protect the module table itself like this (so a reusable function is not required, just a one-off). What is the recommended way of doing that? Probably someone did this before, but my google-foo failed to deliver. So any pointers to/or examples would be appreciated.

Thx!
Thijs