Performance overhead using __index?

["Posti Laatikko" <postilaatikko2002@...>]

I was wondering how much performance overhead is there when using metatable __index?

Meaning how much slower it is to use metatables + __index?

 

I plan to use this

 

function Account:new (o)
      o = o or {}

      setmetatable(o, self)
      self.__index = self
      return o
end

or this

 

function Account:new (o)

    o = o or {}

    Table.Copy(o, self) -- copies self to o

    return o

end