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//Download by http://www.NewXing.com /* * 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: (617) 848-7047 */ #include "bookexcept.h" #include "Sales_item.h" #include <iostream> using std::istream; using std::ostream; // assumes that both objects refer to the same isbn Sales_item& Sales_item::operator+=(const Sales_item& rhs) { units_sold += rhs.units_sold; revenue += rhs.revenue; return *this; } // throws exception if both objects do not refer to the same isbn Sales_item operator+(const Sales_item& lhs, const Sales_item& rhs) { if (!lhs.same_isbn(rhs)) throw isbn_mismatch("isbn mismatch", lhs.book(), rhs.book()); Sales_item ret(lhs); // copy lhs into a local object that we'll return ret += rhs; // add in the contents of rhs return ret; // return ret by value } istream& operator>>(istream& in, Sales_item& s) { double price; in >> s.isbn >> s.units_sold >> price; // check that the inputs succeeded if (in) s.revenue = s.units_sold * price; else s = Sales_item(); // input failed, reset object to default state return in; } ostream& operator<<(ostream& out, const Sales_item& s) { out << s.isbn << "\t" << s.units_sold << "\t" << s.revenue << "\t" << s.avg_price(); return out; } double Sales_item::avg_price() const { if (units_sold) return revenue/units_sold; else return 0; }