C++primer 15.7.4节练习

练习15.27

#include <iostream>
#include <string>
#include <utility>
#include <memory>
#include <vector>

using namespace std;

class Quote {
public:
    Quote() : bookNo(""), price(0.0) { cout << "默认构造函数" << endl; }
    Quote(const string &book, double sales_price) : bookNo(book), price(sales_price) { cout << "构造函数"<< endl; }
    Quote(const Quote& q) : bookNo(q.bookNo), price(q.price) { cout << "拷贝构造函数" << endl; }
    Quote(Quote &&q) noexcept : bookNo(q.bookNo), price(q.price) { cout << "移动构造函数" << endl; }
    Quote& operator=(const Quote& rhs);
    Quote& operator=(Quote&& rhs) noexcept;
    const string& isbn() const { return bookNo; }
    virtual double net_price(size_t n) const { return n * price; }
    virtual ~Quote() = default;
private:
    string bookNo;
protected:
    double price = 0.0;
};

class Disc_quote : public Quote {
public:
    Disc_quote() : Quote() { cout << "派生类默认构造函数" << endl; }
    Disc_quote(const string &book, double sales_price, size_t quan, double dis) : Quote(book, sales_price), quantity(quan), discount(dis) { cout << "派生类构造函数" <<endl; }
    Disc_quote(const Disc_quote& d) : Quote(d), quantity(d.quantity), discount(d.discount) { cout << "派生类拷贝构造函数" <<endl; }
    Disc_quote(Disc_quote&& d) : Quote(std::move(d)), quantity(d.quantity), discount(d.discount) { cout << "派生类移动构造函数" << endl; }
    Disc_quote& operator=(const Disc_quote& rhs);
    Disc_quote& operator=(Disc_quote&& rhs);
    double net_price(size_t n) const override;
    ~Disc_quote() { cout << "派生类析构函数" << endl; }
protected:
    size_t quantity = 0;
    double discount = 0.0;
};

class Bulk_quote : public Disc_quote {
public:
    Bulk_quote() = default;
    Bulk_quote(const string& book, double p, size_t qty, double disc) : Disc_quote(book, p, qty, disc) {}
    double net_price(size_t n) const override;
};

class lim_discount : public Disc_quote {
public:
    using Disc_quote::Disc_quote;
    double net_price(size_t n) const override;
};

double print_total(ostream& os, const Quote& item, size_t t);

int main()
{
    Quote q1;
    Quote q2("C++ primer", 128.00);
    Quote q3(q2);
    Quote q4(std::move(q2));
    print_total(cout, q2, 2);
    q1 = q2;
    q1 = std::move(q2);
    Disc_quote d1;
    Disc_quote d2("C++ plus", 100.32, 5, 0.6);
    Disc_quote d3(d2);
    Disc_quote d4(std::move(d2));
    d1 = d3;
    d1 = std::move(d3);
    Bulk_quote b1;
    system("pause");
    return 0;
}

double print_total(ostream & os, const Quote &item, size_t t)
{
    double ret = item.net_price(t);
    os << "ISBN: " << item.isbn() << " # sold: " << t << " total due: " << ret << endl;
    return ret;
}

double Bulk_quote::net_price(size_t n) const
{
    if (n >= quantity)
        return n * (1 - discount) * price;
    else
        return n * price;
}

double lim_discount::net_price(size_t n) const
{
    if (n <= quantity)
        return n * (1 - discount) * price;
    else
        return Quote::net_price(n);
}

Quote & Quote::operator=(const Quote & rhs)
{
    bookNo = rhs.bookNo;
    price = rhs.price;
    cout << "拷贝赋值运算符" << endl;
    return *this;
    // TODO: 在此处插入 return 语句
}

Quote & Quote::operator=(Quote && rhs) noexcept
{
    bookNo = rhs.bookNo;
    price = rhs.price;
    cout << "移动赋值运算符" << endl;
    return *this;
    // TODO: 在此处插入 return 语句
}

Disc_quote & Disc_quote::operator=(const Disc_quote & rhs)
{
    Quote::operator=(rhs);
    quantity = rhs.quantity;
    discount = rhs.discount;
    cout << "派生类的拷贝构造运算符" << endl;
    return *this;
    // TODO: 在此处插入 return 语句
}

Disc_quote & Disc_quote::operator=(Disc_quote && rhs)
{
    Quote::operator=(rhs);
    quantity = rhs.quantity;
    discount = rhs.discount;
    cout << "派生类移动构造运算符" << endl;
    return *this;
    // TODO: 在此处插入 return 语句
}

double Disc_quote::net_price(size_t n) const
{
    if (n >= quantity)
        return n * (1 - discount) * price;
    else
        return n * price;
}