NULL pointer is the same as deallocating it?

Question

I was working on a piece of code and I was attacked by a doubt: What happens to the memory allocated to a pointer if I assign NULL to that pointer?

For instance:

Answer 1

By assigning NULL to the pointer you will not free allocated memory. You should call deallocation function to free allocated memory. According to C++ Standard 5.3.4/8: "If the allocated type is a non-array type, the allocation function’s name is operator new and the deallocation function’s name is operator delete". I could suggest the following function to safely delete pointers (with assigning NULL to them):

template
inline void SafeDelete( T*& p )
{
    // Check whether type is complete.
    // Deleting incomplete type will lead to undefined behavior
    // according to C++ Standard 5.3.5/5.
    typedef char type_must_be_complete[ sizeof(T)? 1: -1 ];
    (void) sizeof(type_must_be_complete);

    delete p;
    p = NULL;
}