#include <vector>
#include <string>
#include <algorithm>
#include <iostream>
#include <bitset>
#include <cmath>
#include <memory>
using namespace std;

class base {
private:
    int value;

public:
    base(int v) : value(v) {
        printf("base constructor called\n");
    }
    virtual ~base(){
        value = 0;
        printf("base destructor called\n");
    }
    int getValue() {
        printf("base value return: %d\n", value);
        return value;
    }
    void setValue(int _val) { 
        printf("base value change to: %d\n", _val);
        value = _val; 
    }
};

class derived : public base {
private:
    int multi;

public:
    derived(int v, int b) : base(b), multi(v) {
        printf("derived constructor called\n");
    }
    ~derived() {
        printf("derived destructor called\n");
    }

    int domul() {
        return multi * getValue();
    }

    void setMul(int _val) {
        multi = _val;
    }
};


int main(int argc, char* argv[]){
    
    std::shared_ptr<derived> de = std::make_shared<derived>(10, -1);
    std::shared_ptr<base>b = dynamic_pointer_cast<base>(de);
    b->getValue();
    std::shared_ptr<derived> dee = dynamic_pointer_cast<derived>(b);
    cout << "mul:" << dee->domul() << endl;
    dee->setValue(2);
    dee->setMul(1);
    cout << "mul:" << dee->domul() << endl;
    dee = nullptr;
    b = nullptr;
    de = nullptr;
    return 0;
}