Re: Limiting access to variables

[Rob Hoelz <rob@...>]

You could pass an object that delegates to the C++ object, and then
remove that delegation upon deletion.  Here's a quick Lua example:

local realobject = {
 x = 7,
 foo = function(self)
   return self.x
 end,
}

local delegate = setmetatable({}, {__index = realobject, __newindex = realobject})

MyLuaFunctionCalledWithACPlusPlusObject(delegate)
setmetatable(delegate, {__index = function(s, k)
  error('attempt to access ' .. tostring(k) .. ' on dead object')
end, __newindex = function(s, k)
  error('attempt to access ' .. tostring(k) .. ' on dead object')
end)

-Rob

On Wed, 12 May 2010 16:33:05 -0400
"King, Mike" <MKing@klmicrowave.com> wrote:

> My C++ program calls a Lua function with a "wrapped" C++ object as
> one of its parameters.  When the Lua function returns, the object is
> deleted.  How can I prevent future Lua calls from accessing the now
> invalid object?
> 
> 
> 
> 
> 
> 
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