ImpossibleswillHaPPen !!

To be smarter than regular pointers, smart pointers need to do things that regular pointers don't. What could these things be? Probably the most common bugs in C++ (and C) are related to pointers and memory management: dangling pointers, memory leaks, allocation failures and other joys. Having a smart pointer take care of these things can save a lot of aspirin...

The simplest example of a smart pointer is auto_ptr, which is included in the standard C++ library. You can find it in the header , or take a look at Scott Meyers' auto_ptr implementation. Here is part of auto_ptr's implementation, to illustrate what it does:

template class auto_ptr
{
T* ptr;
public:
explicit auto_ptr(T* p = 0) : ptr(p) {}
~auto_ptr() {delete ptr;}
T& operator*() {return *ptr;}
T* operator->() {return ptr;}
// ...
};
As you can see, auto_ptr is a simple wrapper around a regular pointer. It forwards all meaningful operations to this pointer (dereferencing and indirection). Its smartness in the destructor: the destructor takes care of deleting the pointer.