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

Although I think @Mark Ransom is on sort of the right track, I would suggest there's an even more fundamental problem than just assert(this!=NULL).

I think it's much more telling that you're using raw pointers and new (directly) often enough to care. While this isn't (necessarily) a code smell/anti-pattern/whatever in itself, it often points toward code that's unnecessarily similar to C, and isn't taking advantage of the things like containers in the standard library.

Even if the standard containers don't fit your needs well, you can still normally wrap your pointer up into a small enough, simple enough package that techniques like this are irrelevant -- you've restricted access to the pointer in question to such a small amount of code that you can glance through it and assure that it's only ever used when it's valid. As Hoare said, there are two ways of doing things: one is to keep the code so simple there are obviously no deficiencies; the other is to make the code so complex there are no obvious deficiencies. This technique only appears relevant (to me) when you're already dealing with the latter case.

Ultimately, I see the desire to do this at all as basically admitting defeat -- rather than even attempting to assure that the code is correct, you've done the equivalent of setting up a bug-zapper next to a swamp. It reduces the appearance of bugs in a small area by a small percentage, but leaves so many more free to breed that if there's any effect on the total population, it's far too small to measure.