directcall.cpp

《C++ Primer》第四版题解及头文件

/*
 * This file contains code from "C++ Primer, Fourth Edition", by Stanley B.
 * Lippman, Jose Lajoie, and Barbara E. Moo, and is covered under the
 * copyright and warranty notices given in that book:
 * 
 * "Copyright (c) 2005 by Objectwrite, Inc., Jose Lajoie, and Barbara E. Moo."
 * 
 * 
 * "The authors and publisher have taken care in the preparation of this book,
 * but make no expressed or implied warranty of any kind and assume no
 * responsibility for errors or omissions. No liability is assumed for
 * incidental or consequential damages in connection with or arising out of the
 * use of the information or programs contained herein."
 * 
 * Permission is granted for this code to be used for educational purposes in
 * association with the book, given proper citation if and when posted or
 * reproduced.Any commercial use of this code requires the explicit written
 * permission of the publisher, Addison-Wesley Professional, a division of
 * Pearson Education, Inc. Send your request for permission, stating clearly
 * what code you would like to use, and in what specific way, to the following
 * address: 
 * 
 * 	Pearson Education, Inc.
 * 	Rights and Contracts Department
 * 	75 Arlington Street, Suite 300
 * 	Boston, MA 02216
 * 	Fax: [phone]
*/ 

#include "Sales_item.h"
#include <iostream>
using std::cout; using std::endl;

int main()
{
    Sales_item item1, item2;
    std::cin >> item1 >> item2;
    cout << item1 + item2 << endl;
    cout << 42 + 5 << endl;
    cout << endl;

    // equivalent direct call to nonmember operator function
    cout << operator+(item1, item2) << endl;

    item1 += item2;           // expression based ``call''
    item1.operator+=(item2);  // equivalent call to member operator function
    cout << endl;

    return 0;
}