Hello Mansi,
A smart pointer is a C++ class that mimics a regular pointer in syntax and some semantics, but it does more. Because smart pointers to different types of objects tend to have a lot of code in common, almost all good-quality smart pointers in existence are templated by the pointee type, as you can see in the following code:
template <class T>
class SmartPtr
{
public:
explicit SmartPtr(T* pointee) : pointee_(pointee);
SmartPtr& operator=(const SmartPtr& other);
~SmartPtr();
T& operator*() const
{
...
return *pointee_;
}
T* operator->() const
{
...
return pointee_;
}
private:
T* pointee_;
...
};
SmartPtr<T> aggregates a pointer to T in its member variable pointee_. That's what most smart pointers do. In some cases, a smart pointer might aggregate some handles to data and compute the pointer on the fly.
The two operators give SmartPtr pointer-like syntax and semantics. That is, you can write
class Widget
{
public:
void Fun();
};
SmartPtr<Widget> sp(new Widget);
sp->Fun();
(*sp).Fun();
2
