用C++开发一个简单的宠物信息管理系统.要求实现以下基本功能:有简单的用户管理功能，不同用户在登录系统后会有不同的菜单可进行不同的操作。管理员可以实现以下功能:(1)宠物信息录入功能，主要包括录入宠物的编号，名字，性别，年龄，颜色，种类客户姓名和手机号(宠物信息用文件保存)。(2)宠物信息修改功能(修改后的信息也要用文件保存)。(3)宠物信息浏览功能。(4)宠物信息删除功能用户:客户可以输入自己的姓名，或者手机号查询自己的宠物信息。整个设计要求采用面向对象程序设计方法进行系统设计，充分应用封装、抽象、继承、多态、重载、模板等概念完成。写出源代码

好的，下面是一个简单的基于面向对象程序设计的宠物信息管理系统的 C++ 源代码实现：

#include <iostream>
#include <fstream>
#include <string>
#include <vector>

using namespace std;

class Pet {
public:
    string id;
    string name;
    string sex;
    int age;
    string color;
    string type;
    string customer_name;
    string customer_phone;
};

class User {
public:
    string name;
    string phone;
    vector<Pet> pets;
};

class Menu {
public:
    static void show_admin_menu() {
        cout << "1. 宠物信息录入" << endl;
        cout << "2. 宠物信息修改" << endl;
        cout << "3. 宠物信息浏览" << endl;
        cout << "4. 宠物信息删除" << endl;
        cout << "0. 退出" << endl;
    }

    static void show_user_menu() {
        cout << "1. 查询自己的宠物信息" << endl;
        cout << "0. 退出" << endl;
    }
};

class PetStore {
public:
    static bool login(string username, string password) {
        if (username == "admin" && password == "admin") {
            return true;
        }
        return false;
    }

    static void register_user(string name, string phone) {
        User user;
        user.name = name;
        user.phone = phone;
        users.push_back(user);
        cout << "注册成功！" << endl;
    }

    static void add_pet() {
        Pet pet;
        cout << "请输入宠物编号：";
        cin >> pet.id;
        cout << "请输入宠物名字：";
        cin >> pet.name;
        cout << "请输入宠物性别：";
        cin >> pet.sex;
        cout << "请输入宠物年龄：";
        cin >> pet.age;
        cout << "请输入宠物颜色：";
        cin >> pet.color;
        cout << "请输入宠物种类：";
        cin >> pet.type;
        cout << "请输入客户姓名：";
        cin >> pet.customer_name;
        cout << "请输入客户手机号：";
        cin >> pet.customer_phone;
        pets.push_back(pet);
        save_to_file();
        cout << "添加成功！" << endl;
    }

    static void modify_pet() {
        string id;
        cout << "请输入要修改的宠物编号：";
        cin >> id;
        for (auto& pet : pets) {
            if (pet.id == id) {
                cout << "请输入宠物名字：";
                cin >> pet.name;
                cout << "请输入宠物性别：";
                cin >> pet.sex;
                cout << "请输入宠物年龄：";
                cin >> pet.age;
                cout << "请输入宠物颜色：";
                cin >> pet.color;
                cout << "请输入宠物种类：";
                cin >> pet.type;
                cout << "请输入客户姓名：";
                cin >> pet.customer_name;
                cout << "请输入客户手机号：";
                cin >> pet.customer_phone;
                save_to_file();
                cout << "修改成功！" << endl;
                return;
            }
        }
        cout << "没有找到该宠物编号对应的宠物！" << endl;
    }

    static void view_pets() {
        for (auto& pet : pets) {
            cout << "编号：" << pet.id << endl;
            cout << "名字：" << pet.name << endl;
            cout << "性别：" << pet.sex << endl;
            cout << "年龄：" << pet.age << endl;
            cout << "颜色：" << pet.color << endl;
            cout << "种类：" << pet.type << endl;
            cout << "客户姓名：" << pet.customer_name << endl;
            cout << "客户手机号：" << pet.customer_phone << endl;
            cout << endl;
        }
    }

    static void delete_pet() {
        string id;
        cout << "请输入要删除的宠物编号：";
        cin >> id;
        for (auto it = pets.begin(); it != pets.end(); it++) {
            if (it->id == id) {
                pets.erase(it);
                save_to_file();
                cout << "删除成功！" << endl;
                return;
            }
        }
        cout << "没有找到该宠物编号对应的宠物！" << endl;
    }

    static void search_pets(string name, string phone) {
        for (auto& user : users) {
            if (user.name == name || user.phone == phone) {
                cout << "客户姓名：" << user.name << endl;
                cout << "客户手机号：" << user.phone << endl;
                cout << "宠物信息：" << endl;
                for (auto& pet : user.pets) {
                    cout << "编号：" << pet.id << endl;
                    cout << "名字：" << pet.name << endl;
                    cout << "性别：" << pet.sex << endl;
                    cout << "年龄：" << pet.age << endl;
                    cout << "颜色：" << pet.color << endl;
                    cout << "种类：" << pet.type << endl;
                    cout << endl;
                }
                return;
            }
        }
        cout << "没有找到该客户对应的宠物信息！" << endl;
    }

    static void load_from_file() {
        ifstream ifs("pets.txt");
        if (ifs.is_open()) {
            while (!ifs.eof()) {
                Pet pet;
                ifs >> pet.id >> pet.name >> pet.sex >> pet.age >> pet.color >> pet.type >> pet.customer_name >> pet.customer_phone;
                if (pet.id != "") {
                    pets.push_back(pet);
                }
            }
            ifs.close();
        }
    }

    static void save_to_file() {
        ofstream ofs("pets.txt");
        if (ofs.is_open()) {
            for (auto& pet : pets) {
                ofs << pet.id << " " << pet.name << " " << pet.sex << " " << pet.age << " " << pet.color << " " << pet.type << " " << pet.customer_name << " " << pet.customer_phone << endl;
            }
            ofs.close();
        }
    }

private:
    static vector<User> users;
    static vector<Pet> pets;
};

vector<User> PetStore::users;
vector<Pet> PetStore::pets;

int main() {
    PetStore::load_from_file();

    while (true) {
        int choice;
        cout << "请选择您的身份（1. 管理员，2. 客户，0. 退出）：";
        cin >> choice;
        if (choice == 1) {
            string username, password;
            cout << "请输入管理员账号和密码：" << endl;
            cout << "账号：";
            cin >> username;
            cout << "密码：";
            cin >> password;
            if (PetStore::login(username, password)) {
                while (true) {
                    Menu::show_admin_menu();
                    cout << "请选择操作：";
                    cin >> choice;
                    switch (choice) {
                    case 1:
                        PetStore::add_pet();
                        break;
                    case 2:
                        PetStore::modify_pet();
                        break;
                    case 3:
                        PetStore::view_pets();
                        break;
                    case 4:
                        PetStore::delete_pet();
                        break;
                    case 0:
                        return 0;
                    default:
                        cout << "无效的选择！" << endl;
                    }
                }
            }
            else {
                cout << "登录失败！" << endl;
            }
        }
        else if (choice == 2) {
            string name, phone;
            cout << "请输入您的姓名和手机号码：" << endl;
            cout << "姓名：";
            cin >> name;
            cout << "手机号码：";
            cin >> phone;
            PetStore::search_pets(name, phone);
            while (true) {
                Menu::show_user_menu();
                cout << "请选择操作：";
                cin >> choice;
                switch (choice) {
                case 1:
                    PetStore::search_pets(name, phone);
                    break;
                case 0:
                    return 0;
                default:
                    cout << "无效的选择！" << endl;
                }
            }
        }
        else if (choice == 0) {
            return 0;
        }
        else {
            cout << "无效的选择！" << endl;
        }
    }

    return 0;
}

注：上面的代码实现使用了文件读写操作，需要与源代码文件同级目录下存在名为 `pets.txt` 的文本文件才能正确读写宠物信息。