typeid + toString = runtime error

[Ali Çehreli]

On 12/30/2012 08:11 AM, Namespace wrote:
> As far as I know this is because a class destructor is not a finalizer.

Thanks. It is a good way of looking at this issue. Wikipedia describes 
the differences as

"Unlike destructors, finalizers are usually not deterministic. A 
destructor is run when the program explicitly frees an object. In 
contrast, a finalizer is executed when the internal garbage collection 
system frees the object. Depending on the garbage collection method 
used, this may happen at an arbitrary moment after the object is freed, 
possibly never."

(I will continue with the D terminology and call it a destructor.)

Since a class destructor can be executed at any random time, the 
operations that are valid are very limited. Could someone provide a list 
on what can be done and cannot be done. Andrej Mitrovic noted that 
printf works but is that guaranteed, or just happens to work?

Here is my partial list:

* Do not access members of the object that are garbage collected 
themselves. The reason is, those members may have already been finalized.

* Similary, do not access any garbage-collected object.

* (I learned this one in this thread; is this correct?) Do not rely on 
the runtime, as it may have been shutdown already.

* What else?

Ali