main-ptr.cc

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/*
 * Copyright (c) 2006 INRIA
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */
 
#include "ns3/command-line.h"
#include "ns3/object.h"
#include "ns3/ptr.h"
 
#include <iostream>
 
using namespace ns3;
 
class PtrExample : public Object
{
  public:
    PtrExample();
    ~PtrExample() override;
    void Method();
};
 
PtrExample::PtrExample()
{
    std::cout << "PtrExample constructor" << std::endl;
}
 
PtrExample::~PtrExample()
{
    std::cout << "PtrExample destructor" << std::endl;
}
 
void
PtrExample::Method()
{
    std::cout << "PtrExample method" << std::endl;
}
 
static Ptr<PtrExample> g_ptr = nullptr;
 
static Ptr<PtrExample>
StorePtr(Ptr<PtrExample> p)
{
    Ptr<PtrExample> prev = g_ptr;
    g_ptr = p;
    return prev;
}
 
static void
ClearPtr()
{
    g_ptr = nullptr;
}
 
int
main(int argc, char* argv[])
{
    CommandLine cmd(__FILE__);
    cmd.Parse(argc, argv);
 
    {
        // Create a new object of type PtrExample, store it in global
        // variable g_ptr
        Ptr<PtrExample> p = CreateObject<PtrExample>();
        p->Method();
        Ptr<PtrExample> prev = StorePtr(p);
        NS_ASSERT(!prev);
    }
 
    {
        // Create a new object of type PtrExample, store it in global
        // variable g_ptr, get a hold on the previous PtrExample object.
        Ptr<PtrExample> p = CreateObject<PtrExample>();
        Ptr<PtrExample> prev = StorePtr(p);
        // call method on object
        prev->Method();
        // Clear the currently-stored object
        ClearPtr();
        // get the raw pointer and release it.
        PtrExample* raw = GetPointer(prev);
        prev = nullptr;
        raw->Method();
        raw->Unref();
    }
 
    return 0;
}