The object foo is a local variable with type Foo*. That variable likely gets allocated on the stack for the main function, just like any other local variable. But the value stored in foo is a null pointer. It doesn’t point anywhere. There is no instance of type Foo represented anywhere. To call a virtual … Read more
delete performs the check anyway, so checking it on your side adds overhead and looks uglier. A very good practice is setting the pointer to NULL after delete (helps avoiding double deletion and other similar memory corruption problems). I’d also love if delete by default was setting the parameter to NULL like in #define my_delete(x) … Read more
Both (a) and (b) result in undefined behavior. It’s always undefined behavior to call a member function through a null pointer. If the function is static, it’s technically undefined as well, but there’s some dispute. The first thing to understand is why it’s undefined behavior to dereference a null pointer. In C++03, there’s actually a … Read more