Is “delete p; p = NULL(nullptr);” an antipattern?

Question

Searching something on SO, I stumbled across this question and one of the comments to the most voted answer (the fifth comment to that most voted answer) suggests that del

Answer 1

Yes, I would not recommended doing it.

The reason is that the extra setting to null will only help in very limited contexts. If you are in a destructor, the pointer itself will not exist right after the destructor execution, which means that whether it is null or not does not matter.

If the pointer was copied, setting p to null will not set the rest of the pointers, and you can then hit the same problems with the extra issue that you will be expecting to find deleted pointers being null, and it won't make sense how your pointer became non-zero and yet the object is not there....

Additionally it might hide other errors, like for example if your application is trying to delete a pointer many times, by setting the pointer to null, the effect is that the second delete will be converted to a no-op, and while the application will not crash the error in the logic is still there (consider that a later edit accesses the pointer right before the delete that is not failing... how can that fail?