使用共享指针向量时，从基类强制转换为特定的派生类

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

class Base {
public:
    virtual void print() {
        std::cout << "This is the base class." << std::endl;
    }
};

class Derived : public Base {
public:
    void print() override {
        std::cout << "This is the derived class." << std::endl;
    }
};

int main() {
    std::vector<std::shared_ptr<Base>> vec;
    vec.push_back(std::make_shared<Base>());
    vec.push_back(std::make_shared<Derived>());

    for (const auto& ptr : vec) {
        std::shared_ptr<Derived> derivedPtr = std::dynamic_pointer_cast<Derived>(ptr);
        if (derivedPtr) {
            derivedPtr->print();
        }
    }

    return 0;
}

This is the derived class.