C / C++ / MFC

struct datastruct_base
{
  virtual ~datastruct_base()=0{}
  virtual void put(const void* arg)=0;
  virtual void get(void* arg)=0;
};

template<typename type>
struct datastruct: public datastruct_base
{
  virtual void put(const void* arg)
  {
    put(static_cast<const type*>(arg));
  }
  virtual void get(void* arg)
  {
    get(static_cast<type*>(arg));
  }
  void put(const type* arg)
  {
    ...
  }
  void get(type* arg)
  {
    ...
  }
};

class host{
private:
  datastruct_base* ds;
public:
  void set_datastruct(datastruct_base* ds){this->ds=ds;}
  void put(const void* arg){ds->put(arg);}
  void get(void* arg){ds->get(arg);}
};
 
host hs;
datastruct<int> dsi;
hs.set(&dsi);
int i=10;
hs.put(&i);
hs.get(&i);

MyObject* myObject = NULL;
myObject = new MyObject;

delete myObject;
myObject = NULL; // always do this.