编辑“︁C++ 责任链模式”︁（章节）

== 代码示例 ==
以下是一个简单的C++实现，展示责任链模式的基本用法：

<syntaxhighlight lang="cpp">
#include <iostream>
#include <string>

// 请求类
class Request {
public:
    std::string type;
    int value;
    Request(const std::string& t, int v) : type(t), value(v) {}
};

// 处理者接口
class Handler {
protected:
    Handler* nextHandler;
public:
    Handler() : nextHandler(nullptr) {}
    virtual ~Handler() = default;
    
    void setNext(Handler* handler) {
        nextHandler = handler;
    }
    
    virtual void handleRequest(const Request& req) = 0;
};

// 具体处理者A
class ConcreteHandlerA : public Handler {
public:
    void handleRequest(const Request& req) override {
        if (req.type == "TypeA") {
            std::cout << "ConcreteHandlerA 处理了类型为 " << req.type 
                      << " 的请求，值为 " << req.value << std::endl;
        } else if (nextHandler != nullptr) {
            nextHandler->handleRequest(req);
        } else {
            std::cout << "没有处理者能处理此请求" << std::endl;
        }
    }
};

// 具体处理者B
class ConcreteHandlerB : public Handler {
public:
    void handleRequest(const Request& req) override {
        if (req.type == "TypeB") {
            std::cout << "ConcreteHandlerB 处理了类型为 " << req.type 
                      << " 的请求，值为 " << req.value << std::endl;
        } else if (nextHandler != nullptr) {
            nextHandler->handleRequest(req);
        } else {
            std::cout << "没有处理者能处理此请求" << std::endl;
        }
    }
};

int main() {
    // 创建处理链
    Handler* handlerA = new ConcreteHandlerA();
    Handler* handlerB = new ConcreteHandlerB();
    handlerA->setNext(handlerB);
    
    // 创建请求
    Request req1("TypeA", 10);
    Request req2("TypeB", 20);
    Request req3("TypeC", 30);
    
    // 发送请求
    handlerA->handleRequest(req1);
    handlerA->handleRequest(req2);
    handlerA->handleRequest(req3);
    
    delete handlerA;
    delete handlerB;
    return 0;
}
</syntaxhighlight>

'''输出结果：'''
<pre>
ConcreteHandlerA 处理了类型为 TypeA 的请求，值为 10
ConcreteHandlerB 处理了类型为 TypeB 的请求，值为 20
没有处理者能处理此请求
</pre>