Do I need to nullify a member variable in the destructor?

Question

Why one would want to explicitly clear the a vector member variable (of on in a dtor (please see the code below). what are the benefits of clearing the vector, even though i

Answer 1

In your second example there's no reason to set p_ to null whatsoever, specifically because it is done in the destructor, meaning that the lifetime of p_ will end immediately after that.

Moreover, there's no point in comparing p_ to null before calling delete, since delete expression performs this check internally. In your specific artificial example, the destructor should simply contain delete p_ and noting else. No if, no setting p_ to null.