继承构造函数

class Base {
public:
    Base(int);
    Base(const std::string&);
    Base(int, double);
};

class Derived : public Base {
public:
    using Base::Base;  // 继承 Base 的全部构造函数
    // 效果等同于为 Base 的每个构造函数写了透传版本
};

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

// 基类：通知消息
class Notification {
public:
    Notification() : title_("系统通知"), priority_(0) {
        std::cout << "  [默认构造] " << title_ << std::endl;
    }

    Notification(std::string title, int priority)
        : title_(std::move(title)), priority_(priority) {
        std::cout << "  [主构造] " << title_
                  << " (优先级: " << priority_ << ")" << std::endl;
    }

    explicit Notification(std::string title)
        : Notification(std::move(title), 1) {}  // 委托构造

    virtual ~Notification() = default;

    virtual void display() const {
        std::cout << "[" << priority_ << "] " << title_ << std::endl;
    }

protected:
    std::string title_;
    int priority_;
};

// 派生类：系统警告 —— 继承基类全部构造函数
class SystemAlert : public Notification {
public:
    using Notification::Notification;  // C++11 继承构造函数

    void display() const override {
        std::cout << "⚠️ 系统警告: " << title_
                  << " (级别 " << priority_ << ")" << std::endl;
    }
};

// 派生类：用户消息 —— 同样继承
class UserMessage : public Notification {
public:
    using Notification::Notification;

    void display() const override {
        std::cout << "📩 用户消息: " << title_
                  << " (优先级 " << priority_ << ")" << std::endl;
    }
};

int main() {
    std::cout << "===== 飞翔科技通知中心 =====" << std::endl;

    std::cout << "\n-- 创建 SystemAlert 对象 --" << std::endl;
    SystemAlert alert1("数据库连接超时", 5);
    SystemAlert alert2("磁盘空间不足");     // 单参数：委托到主构造
    SystemAlert alert3;                      // 默认构造

    std::cout << "\n-- 创建 UserMessage 对象 --" << std::endl;
    UserMessage msg1("孔蓝提交了需求文档", 2);
    UserMessage msg2("版本发布通知");

    std::cout << "\n-- 通知列表 --" << std::endl;
    alert1.display();
    alert2.display();
    alert3.display();
    msg1.display();
    msg2.display();

    return 0;
}

#include <iostream>
#include <string>

// 基类 A：记录创建日志
class Logger {
public:
    Logger(const std::string& category) : category_(category) {
        std::cout << "[Logger] 创建日志分类: " << category_ << std::endl;
    }

    Logger(int verbosity) : verbosity_(verbosity) {
        std::cout << "[Logger] 详细级别: " << verbosity_ << std::endl;
    }

    const std::string& category() const { return category_; }
    int verbosity() const { return verbosity_; }

private:
    std::string category_ = "default";
    int verbosity_ = 0;
};

// 基类 B：记录时间戳
class Timestamp {
public:
    Timestamp(const std::string& format) : format_(format) {
        std::cout << "[Timestamp] 时间格式: " << format_ << std::endl;
    }

    Timestamp(int precision) : precision_(precision) {
        std::cout << "[Timestamp] 精度: " << precision_ << " 位" << std::endl;
    }

    const std::string& format() const { return format_; }
    int precision() const { return precision_; }

private:
    std::string format_ = "ISO";
    int precision_ = 3;
};

// 多重继承：两个基类都有 string 和 int 构造函数——签名冲突
class AuditLog : public Logger, public Timestamp {
public:
    // 签名冲突：Logger(string) 和 Timestamp(string) 都是 string 参数
    // 签名冲突：Logger(int) 和 Timestamp(int) 都是 int 参数
    // 无法直接 using Logger::Logger; using Timestamp::Timestamp;

    // 解决方案：手动消歧
    using Logger::Logger;
    using Timestamp::Timestamp;

    // 当两个基类都有相同签名的构造函数时，该签名的继承会被"禁用"
    // 必须手动实现：
    AuditLog(const std::string& category)
        : Logger(category), Timestamp("ISO") {}  // 手动消歧

    AuditLog(int level)
        : Logger(level), Timestamp(level) {}      // 手动消歧

    void report() const {
        std::cout << "[AuditLog] " << category()
                  << " | " << format()
                  << " | 详细度 " << verbosity() << std::endl;
    }
};

int main() {
    std::cout << "===== 飞翔科技审计日志 =====" << std::endl;

    std::cout << "\n-- 冲突签名：string --" << std::endl;
    AuditLog log1("系统操作");

    std::cout << "\n-- 冲突签名：int --" << std::endl;
    AuditLog log2(5);

    std::cout << "\n-- 审计报告 --" << std::endl;
    log1.report();
    log2.report();

    return 0;
}