What is some reward/drawback of using friend functions?, C/C++ Programming

Assignment Help:

A: They present a degree of freedom in the interface design options.

Member functions & friend functions are equally privileged (100% vested). The major difference is that a friend function is called such as f(x), whereas a member function is called like x.f(). Therefore the ability to select between member functions (x.f()) and friend functions (f(x)) let a designer to choose the syntax that is deemed most readable, which lowers maintenance costs.

The major disadvantage of friend functions is that they need an extra line of code while you wished dynamic binding. In order to get the effect of a virtual friend, the friend function must call a hidden (usually protected) virtual member function. It is called the Virtual Friend Function Idiom. For instance:

class Base {

public:

friend void f(Base& b);

... protected:

virtual void do_f();

...

};

inline void f(Base& b)

{

b.do_f();

}

class Derived : public Base {

public:

... protected:

virtual void do_f(); // "Override" the behavior of f(Base& b)

...

};

void userCode(Base& b)

{

f(b);

}

In userCode(Base&) , the statement f(b) will invoke b.do_f(), that is virtual. It means that Derived::do_f() will get control actually if b is a object of class Derived. Note down that Derived overrides behavior of the protected virtual member function do_f(); this does not have its own variation of the friend function, f(Base&).


Related Discussions:- What is some reward/drawback of using friend functions?

Define the data file in c programming, Define the Data File in C Programmin...

Define the Data File in C Programming? Many applications needs that information can written to or read from an auxiliary memory device. Such information is stock up on the memo

Amie, what happens when the following command is used? chmod u=rwx,go=r-x f...

what happens when the following command is used? chmod u=rwx,go=r-x foo

Miss, Depreciation to a salvage value of 0. For tax purposes an item m...

Depreciation to a salvage value of 0. For tax purposes an item may be depreciated over a period of several years, n. With the straight line method of depreciati

PLS URGENT HELP WITH C++, Pls i only need help with program 2. #include ...

Pls i only need help with program 2. #include #include using namespace std; int main() { int FilingStatus; cout cout cout cout cout cout

What are the differences among a struct in c & in c++?, A: In C++ a struct ...

A: In C++ a struct is alike to a class except for the default access specifier( refer to other question in the document). In C we ought to include the struct keyword while declarin

Subtraction of numbers, Two numbers to be subtracted using bitwise operatio...

Two numbers to be subtracted using bitwise operations

Luminous Jewels - The Polishing Game, Byteland county is very famous for lu...

Byteland county is very famous for luminous jewels. Luminous jewels are used in making beautiful necklaces. A necklace consists of various luminous jewels of particular colour. Nec

Pointer to function, Pointer to function: int mul(int a, int b, int c) ...

Pointer to function: int mul(int a, int b, int c) {   return a*b*c; } void main() {   int (*function_pointer)(int, int, int);   function_pointer = &mul;

Areaundercurve.c, Write a program to find the area under the curve y = f(x)...

Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b. The area under a curve betw   Solution:

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