#include <iostream>

using namespace std;

struct AbstractResource {
  int ref_count;
  virtual void do_something() = 0;
  AbstractResource() : ref_count(0) {}
  virtual ~AbstractResource(){}
};

struct Resource0 : public AbstractResource {
  void do_something(){
    cout << "Do somthing with Resource0 at " << this << endl;
  }
  Resource0() : AbstractResource() {
    cout << "Cerated Resource0 at " << this << endl;
  }
  ~Resource0(){
    cout << "Clean-uped Resource0 at " << this << endl;
  }
};

struct Resource1 : public AbstractResource {
  void do_something(){
    cout << "Do somthing with Resource1 at " << this << endl;
  }
  Resource1() : AbstractResource() {
    cout << "Cerated Resource1 at " << this << endl;
  }
  ~Resource1(){
    cout << "Clean-uped Resource1 at " << this << endl;
  }
};

struct Resource {
  AbstractResource *delegatee;
  void do_something() {
    delegatee->do_something();
  }
  Resource(AbstractResource *resource) 
      : delegatee(resource) {
    (delegatee->ref_count)++;
  }
  Resource(const Resource &orig)
      : delegatee(orig.delegatee) {
    (delegatee->ref_count)++;
  }
  Resource &operator=(const Resource &rhs){
    if(delegatee != rhs.delegatee){
      if(--(delegatee->ref_count) <= 0){
        delete delegatee;
      }
      delegatee = rhs.delegatee;
      (delegatee->ref_count)++;
    }
    return *this;
  }
  ~Resource() {
    if(--(delegatee->ref_count) < 1){
      delete delegatee;
    }
  }
};

struct ResourceManager {
  static Resource get_resource(const int &type){
    return Resource((type != 0) 
        ? (AbstractResource *)new Resource1() 
        : (AbstractResource *)new Resource0()); 
  }
};

int main() {
  Resource r0(ResourceManager::get_resource(0));
  r0.do_something();
  
  Resource r1(ResourceManager::get_resource(1));
  r1.do_something();
  
  {
    Resource r0_copy(r0);
    r0_copy.do_something();
    
    Resource r1_another(ResourceManager::get_resource(1));
    r1_another.do_something();
  }
  
  return 0;
}

Cerated Resource0 at 0x8051438
Do somthing with Resource0 at 0x8051438
Cerated Resource1 at 0x8051568
Do somthing with Resource1 at 0x8051568
Do somthing with Resource0 at 0x8051438
Cerated Resource1 at 0x8051590
Do somthing with Resource1 at 0x8051590
Clean-uped Resource1 at 0x8051590
Clean-uped Resource1 at 0x8051568
Clean-uped Resource0 at 0x8051438