How can i provide printing for whole hierarchy of classes?, C/C++ Programming

Assignment Help:

A: Provide a friend operator<< which calls a protected virtual function

class Base {

public:

friend std::ostream& operator<< (std::ostream& o, const Base& b);

... protected:

virtual void printOn(std::ostream& o) const;

};

inline std::ostream& operator<< (std::ostream& o, const Base& b)

{ b.printOn(o); return o;

}

class Derived : public Base {

protected:

virtual void printOn(std::ostream& o) const;

};

The ending result is that operator<< acts as if it were bound dynamically, even though it's a friend function. It is called the Virtual Friend Function Idiom.

Note down that derived classes override printOn(std::ostream&) const. Particularly, they do not provide their own operator<<.

Of course if Base is an ABC, Base::printOn(std::ostream&) const may be declared pure virtual using the "= 0" syntax.

!    

 


Related Discussions:- How can i provide printing for whole hierarchy of classes?

C program for function of copy one string in other string, C Program for FU...

C Program for FUNCTION OF COPY ONE STRING IN OTHER STRING #include stdio.h> #include conio.h> int copy(char a[],char b[]); void main() {           char a[100],b[

I need profile and optimize a c++ library for speed, I need Profile and opt...

I need Profile and optimize a C++ library for speed Project Description: Optimize and profile an existing C++ library for speed. This library uses OpenMP and OpenCV and C+

Big-m method, big-m method operation reseach in progrmme c++..

big-m method operation reseach in progrmme c++..

Plz reply on [email protected], You are to implement a code cracking ...

You are to implement a code cracking system. The system will deploy four processes (p1,p2,p3 & p4) to try to guess the password of an encrypted code. For encryption, we consider th

Write a simple telephone book program, Write a simple telephone book progra...

Write a simple telephone book program that stores the names and phone numbers of your friends/acquaintances in a file. Your program should have the abilities to: a. Add entries (n

Recursive procedure to computes the number of digits, (a) Write a recursive...

(a) Write a recursive procedure (digits n) that computes the number of digits in the integer n using a linear recursive process. For example, (digits 42) should return 2 and (digit

Non-maxima suppression, Use the program called harris-shell.c and add some ...

Use the program called harris-shell.c and add some code to find the corners in the image checkers.jpg. You should say that a pixel in the image is a corner if it passes the given t

Array, write a function that take as parameters an array of integer and its...

write a function that take as parameters an array of integer and its size and return the sum of its value

UltimateCarRadio Project, In this assignment, you will be modifying your As...

In this assignment, you will be modifying your Assign-05 code to use more inheritance. As well, in this assignment, you will be asked to use newand delete, throw and catch except

Named what can derived class add?, New data members  New member function...

New data members  New member functions  New constructors and destructor  New friends

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd