関連ワード:  write a c++ program to perform friend function    write a c++ program to implement friend function    write a c++ program to demonstrate friend function    write a c++ program to illustrate friend function    write a c++ program using friend function    write a c++ program to demonstrate example of friend function with class    define friend function in c++    friend function in c++ with example  
結果 : write a c++ program to perform friend function