第1章 C++开始

Posted 2021-11-07 COCO_PEAK_NOODLE

由于自己C++基础薄弱，来重新补习一下，很好奇我是怎么把cartographer啃下来的

1- cin 运算符重载

std::istream& 
operator>>(std::istream& in, Sales_item& s)
{
    double price;
    in >> s.bookNo >> 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;
}

2- +号运算符重载

Sales_item& Sales_item::operator+=(const Sales_item& rhs) 
{
    units_sold += rhs.units_sold; 
    revenue += rhs.revenue; 
    return *this;
}