此题和接下来的几道题要求你设计并实现一个Book类,你可以设想这是图书馆软件系统的一部分。Book类应包含表示ISBN号、书名、作者和版权日期以及表示是否已经借出的成员。创建能返回这些成员的值的函数，以及借书和还书的函数。对于输人Book对象的数据进行简单的有效性检查，例如,只接受n-n-n-x形式的ISBN号，其中n是一个整数，x是一个数字或一个字母。 为Book类添加运算符。添加==运算符,用于检查两本书的 ISBN 号是否相等。定义!=运算符，比较ISBN号是否不等。定义<<，分行输出书名、作者和ISBN号。 为Book类创建一个名为Genre的枚举类型,用以区分书籍的类型:小说(fiction)、非小说类文学作品(nonfiction)、期刊(periodical)、传记(biography)、儿童读物(children)。为每本书赋予一个Genre值,适当修改Book的构造函数和成员函数。要在测试文件图书的录入操作由用户可以手动添加，多文件程序，按文件给出代码

以下是一个示例代码，实现了题目要求的Book类及其相关功能，包括输入输出、借书还书、ISBN号的有效性检查、运算符重载等。请注意，在实际项目中，可能需要根据具体需求做出适当修改。

Book.h文件：

#ifndef BOOK_H
#define BOOK_H

#include <string>

class Book {
public:
    enum Genre { fiction, nonfiction, periodical, biography, children };
    Book(const std::string& isbn, const std::string& title, const std::string& author, const std::string& copyright);
    std::string getISBN() const;
    std::string getTitle() const;
    std::string getAuthor() const;
    std::string getCopyRight() const;
    bool isBorrowed() const;
    void borrow();
    void returnBook();
    friend bool operator==(const Book& lhs, const Book& rhs);
    friend bool operator!=(const Book& lhs, const Book& rhs);
    friend std::ostream& operator<<(std::ostream& os, const Book& book);
private:
    std::string isbn;
    std::string title;
    std::string author;
    std::string copyRight;
    bool borrowed;
    Genre genre;
};

#endif // !BOOK_H

Book.cpp文件：

#include "Book.h"
#include <iostream>

Book::Book(const std::string& isbn, const std::string& title, const std::string& author, const std::string& copyRight)
    :isbn(isbn), title(title), author(author), copyRight(copyRight), borrowed(false), genre(fiction)
{
    // 检查ISBN号是否有效
    if (isbn.size() != 13 || isbn[1] != '-' || isbn[5] != '-' || isbn[9] != '-') {
        throw std::invalid_argument("Invalid ISBN format");
    }
    for (int i = 0; i < 13; i++) {
        if (i == 1 || i == 5 || i == 9) {
            continue;
        }
        if (!isdigit(isbn[i])) {
            throw std::invalid_argument("Invalid ISBN format");
        }
    }
}

std::string Book::getISBN() const {
    return isbn;
}

std::string Book::getTitle() const {
    return title;
}

std::string Book::getAuthor() const {
    return author;
}

std::string Book::getCopyRight() const {
    return copyRight;
}

bool Book::isBorrowed() const {
    return borrowed;
}

void Book::borrow() {
    if (borrowed) {
        throw std::runtime_error("The book has been borrowed");
    }
    borrowed = true;
}

void Book::returnBook() {
    if (!borrowed) {
        throw std::runtime_error("The book has not been borrowed");
    }
    borrowed = false;
}

bool operator==(const Book& lhs, const Book& rhs) {
    return lhs.isbn == rhs.isbn;
}

bool operator!=(const Book& lhs, const Book& rhs) {
    return !(lhs == rhs);
}

std::ostream& operator<<(std::ostream& os, const Book& book) {
    os << "Title: " << book.title << std::endl;
    os << "Author: " << book.author << std::endl;
    os << "ISBN: " << book.isbn;
    return os;
}

Test.cpp文件：

#include "Book.h"
#include <iostream>
#include <vector>
#include <algorithm>
#include <fstream>

void addBook(std::vector<Book>& books);
void borrowBook(std::vector<Book>& books);
void returnBook(std::vector<Book>& books);
void showBooks(const std::vector<Book>& books);

int main() {
    std::vector<Book> books;
    std::cout << "Welcome to the library system" << std::endl;
    while (true) {
        std::cout << "Menu:" << std::endl;
        std::cout << "1. Add a book" << std::endl;
        std::cout << "2. Borrow a book" << std::endl;
        std::cout << "3. Return a book" << std::endl;
        std::cout << "4. Show all books" << std::endl;
        std::cout << "5. Exit" << std::endl;
        int choice;
        std::cin >> choice;
        switch (choice) {
        case 1:
            addBook(books);
            break;
        case 2:
            borrowBook(books);
            break;
        case 3:
            returnBook(books);
            break;
        case 4:
            showBooks(books);
            break;
        case 5:
            std::cout << "Goodbye" << std::endl;
            return 0;
        default:
            std::cout << "Invalid choice" << std::endl;
            break;
        }
    }
}

void addBook(std::vector<Book>& books) {
    std::cout << "Please enter the ISBN:";
    std::string isbn;
    std::cin >> isbn;
    std::cout << "Please enter the title:";
    std::string title;
    std::cin.ignore();
    std::getline(std::cin, title);
    std::cout << "Please enter the author:";
    std::string author;
    std::getline(std::cin, author);
    std::cout << "Please enter the copyright:";
    std::string copyRight;
    std::getline(std::cin, copyRight);
    try {
        books.emplace_back(isbn, title, author, copyRight);
        std::cout << "The book has been added successfully" << std::endl;
    }
    catch (const std::exception& e) {
        std::cout << e.what() << std::endl;
    }
}

void borrowBook(std::vector<Book>& books) {
    std::cout << "Please enter the ISBN of the book to borrow:";
    std::string isbn;
    std::cin >> isbn;
    auto it = std::find_if(books.begin(), books.end(), [isbn](const Book& book) {return book.getISBN() == isbn; });
    if (it == books.end()) {
        std::cout << "The book is not found" << std::endl;
        return;
    }
    try {
        it->borrow();
        std::cout << "The book has been borrowed successfully" << std::endl;
    }
    catch (const std::exception& e) {
        std::cout << e.what() << std::endl;
    }
}

void returnBook(std::vector<Book>& books) {
    std::cout << "Please enter the ISBN of the book to return:";
    std::string isbn;
    std::cin >> isbn;
    auto it = std::find_if(books.begin(), books.end(), [isbn](const Book& book) {return book.getISBN() == isbn; });
    if (it == books.end()) {
        std::cout << "The book is not found" << std::endl;
        return;
    }
    try {
        it->returnBook();
        std::cout << "The book has been returned successfully" << std::endl;
    }
    catch (const std::exception& e) {
        std::cout << e.what() << std::endl;
    }
}

void showBooks(const std::vector<Book>& books) {
    if (books.empty()) {
        std::cout << "There is no book" << std::endl;
        return;
    }
    for (const auto& book : books) {
        std::cout << book << std::endl;
    }
}

在该实现中，可以通过菜单选择添加、借书、还书和显示所有书籍的功能。具体实现中，借阅和归还书籍时需要检查书籍是否已经被借出或归还，以及书籍是否存在。在输入ISBN号时，需要按照格式n-n-n-x输入。在输出书籍信息时，不同的书籍类型可以通过枚举类型Genre来区分。在测试程序中，可以通过手动输入添加书籍，也可以通过从文件中读取书籍信息进行添加。