[瞎JB写] C++多态

#include <iostream>
#include <vector>
#include <memory>
using namespace std;

class A {
public:
    virtual void init() = 0;
};

class B : public A {
public:
    void init() {
        cout << "B init" << endl;
    }
};

class C :public B {
public:
    void print() {
        cout << "C -> B" << endl;
    }
    void init() {
        cout << "C init" << endl;
    }
};

class D : public A {
private:
    int wow;
public:
    D() { wow = 0; }
    D(int a) :wow(a) {}
    void init() {
        cout << "D init" << endl;
    }
    void print() {
        cout << "D -> A" << wow << endl;
    }
};

int main() {
    vector<shared_ptr<A>> list;
    list.push_back(make_shared<C>());
    list.push_back(make_shared<D>(1));
    for (auto &item : list) {
        item->init();
    }
    ((D*)list[1].get())->print();
    return 0;
}

#define PTR_CONVERT(shared_ptr, type) ((type*)shared_ptr.get())

PTR_CONVERT(list[0], C)->print();
PTR_CONVERT(list[1], D)->print();