使用C++模板实现访问者模式

#include<iostream>
#include<vector>

// 访问者类
class Visitor {
public:
    template<typename T>
    void visit(T& element) {
        std::cout << "Visiting "<< element.getName()<< std::endl;
    }
};

// 元素类
class Element {
public:
    Element(const std::string& name) : m_name(name) {}
    virtual ~Element() {}

    std::string getName() const {
        return m_name;
    }

private:
    std::string m_name;
};

// 具体元素类A
class ConcreteElementA : public Element {
public:
    ConcreteElementA(const std::string& name) : Element(name) {}

    void accept(Visitor& visitor) {
        visitor.visit(*this);
    }
};

// 具体元素类B
class ConcreteElementB : public Element {
public:
    ConcreteElementB(const std::string& name) : Element(name) {}

    void accept(Visitor& visitor) {
        visitor.visit(*this);
    }
};

int main() {
    std::vector<Element*> elements;
    elements.push_back(new ConcreteElementA("ElementA"));
    elements.push_back(new ConcreteElementB("ElementB"));

    Visitor visitor;
    for (auto& element : elements) {
        element->accept(visitor);
    }

    for (auto& element : elements) {
        delete element;
    }

    return 0;
}