Re: userdata and the gc

[David Jones <drj@...>]

On Apr 18, 2006, at 06:45, Adrian Sietsma wrote:

> Will a userdata's address change when the gc runs ?
>
> ie:
>
> lua_pushstring(L,"foo");
> p = lua_newuserdata(L,sizeof(foo));
> lua_rawset(L,LUA_REGISTRYINDEX);
>
> ... do something to force a gc
>
> lua_pushstring(L,"foo");
> lua_rawget(L,LUA_REGISTRYINDEX);
> p1 = lua_touserdata(L,-1);
> assert (p==p1); <----------------

The documentation doesn't say explicitly either way.

I think the specification should be similar to the lua_tolstring case, 
the pointer returned will not be valid when the corresponding value is 
removed from the stack.

drj