#include<iostream>
#include<memory>
using namespace std;
class base : public enable_shared_from_this<base> {
public:base(int n = 0) :x(n) {}int x;virtual void print(){cout << "self_shared:" << x << endl;}~base() {cout << "this is base class" << endl;}
};class derive :public base {
public:virtual void print(){cout << "derive" << endl;}~derive(){cout << "this is derive class" << endl;}
};void test(const shared_ptr<base>& value1, const shared_ptr<base>& value2) {value1->print();value2->print();
}int main()
{shared_ptr<base> p1 = shared_ptr<derive>(new derive());p1->print();//shared_ptr<base> p1 = shared_ptr<base>(new base(22));//p1->print();//shared_ptr<base> sp = make_shared<base>(111);//sp->print();//test(make_shared<base>(1), make_shared<base>(2));return 0;
}

class Stock {string key_;
public:Stock(const string& k):key_(k){}const string& key(){return key_;}};class StockFactory: public enable_shared_from_this<StockFactory> {map <string, weak_ptr<Stock>> stocks_;
public:StockFactory() {cout << "the StockFactory is create" << endl;}~StockFactory() {cout << "destory StockFactory!!!!" << endl;}shared_ptr<Stock> get(const string& key) {shared_ptr<Stock> pStock;weak_ptr<Stock>& wkStock = stocks_[key];pStock = wkStock.lock();if (!pStock) {pStock.reset(new Stock(key), std::bind(&StockFactory::deleteStock, shared_from_this(), std::placeholders::_1));wkStock = pStock;}return pStock;}private:void deleteStock(Stock* stock) {if (stock) {            cout << "deleteStock" << endl;stocks_.erase(stock->key());}delete stock;}
};int main()
{shared_ptr<Stock> p2;    {shared_ptr<StockFactory> p1 = make_shared<StockFactory>();p2 = p1->get("google");cout << p1.use_count() << endl;}return 0;
}