/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */

#include "ns3/ptr.h"

#include "ns3/object.h"

#include <iostream>

using namespace ns3;

class A : public Object

{

public:

  A ();

  ~A ();

  void Method (void);

};

A::A ()

{

  std::cout << "A constructor" << std::endl;

}

A::~A()

{

  std::cout << "A destructor" << std::endl;

}

void

A::Method (void)

{

  std::cout << "A method" << std::endl;

}

static Ptr<A> g_a = 0;

static Ptr<A>

StoreA (Ptr<A> a)

{

  Ptr<A> prev = g_a;

  g_a = a;

  return prev;

}

static void

ClearA (void)

{

  g_a = 0;

}

int main (int argc, char *argv[])

{

  {

    // Create a new object of type A, store it in global 

    // variable g_a

    Ptr<A> a = CreateObject<A> ();

    a->Method ();

    Ptr<A> prev = StoreA (a);

    NS_ASSERT (prev == 0);

  }

  {

    // Create a new object of type A, store it in global 

    // variable g_a, get a hold on the previous A object.

    Ptr<A> a = CreateObject<A> ();

    Ptr<A> prev = StoreA (a);

    // call method on object

    prev->Method ();

    // Clear the currently-stored object

    ClearA ();

    // get the raw pointer and release it.

    A *raw = GetPointer (prev);

    prev = 0;

    raw->Method ();

    raw->Unref ();

  }

  return 0;

}