What is a smart pointer?



What is a smart pointer?..

Answer / akhilesh kumar jaiswal

A smart pointer is an object that acts, looks and feels like a normal pointer but offers more functionality. In C++, smart pointers are implemented as template classes that encapsulate a pointer and override standard pointer operators. They have a number of advantages over regular pointers. They are guaranteed to be initialized as either null pointers or pointers to a heap object. Indirection through a null pointer is checked. No delete is ever necessary. Objects are automatically freed when the last pointer to them has gone away. One significant problem with these smart pointers is that unlike regular pointers, they don't respect inheritance. Smart pointers are unattractive for polymorphic code. Given below is an example for the implementation of smart pointers.
Example:
template <class X>
class smart_pointer
{
public:
smart_pointer(); // makes a null pointer
smart_pointer(const X& x) // makes pointer to copy of x

X& operator *( );
const X& operator*( ) const;
X* operator->() const;

smart_pointer(const smart_pointer <X> &);
const smart_pointer <X> & operator =(const smart_pointer<X>&);
~smart_pointer();
private:
//...
};
This class implement a smart pointer to an object of type X. The object itself is located on the heap. Here is how to use it:
smart_pointer <employee> p= employee("Harris",1333);
Like other overloaded operators, p will behave like a regular pointer,
cout<<*p;
p->raise_salary(0.5);

Is This Answer Correct ?    0 Yes 0 No

Post New Answer

More C++ General Interview Questions

Is there something that we can do in C and not in C++?

14 Answers   Patni,


Which bit wise operator is suitable for turning off a particular bit in a number?

0 Answers  


What is the exit function in c++?

0 Answers  


What do you understand by pure virtual function? Write about its use?

0 Answers  


Can recursive program be written in C++?

0 Answers  






What are the differences between a struct in C and in C++?

8 Answers   Amazon, Wipro,


Explain how would you handle a situation where you cannot call the destructor of a local explicitly?

0 Answers  


What is a flag in c++?

0 Answers  


What is c++ stringstream?

0 Answers  


What is a virtual destructor?

2 Answers  


How do you define a class in c++?

0 Answers  


What does asterisk mean in c++?

0 Answers  


Categories