Re: [Boost-users] Smart pointers

From: Andrew Holden (aholden_at_[hidden])
Date: 2007-05-10 14:25:07

#include <boost/shared_ptr.hpp>

#include <boost/weak_ptr.hpp>

 

class A
{
   // ...
   boost::weak_ptr <B> m_b;  //Use a weak pointer to break cycles
};

class B
{
   // ...
   std::vector<boost::shared_ptr <A> > m_a;
};

 

 

If B uses a member function to allocate A and/or add A to the vector, then B would become something like this:

 

#include <boost/enable_shared_from_this.hpp>

 

class B: public boost::enable_shared_from_this <B>
{

  void add_an_A (boost::shared_ptr <A> new_a)

  {

    new_a->m_b = shared_from_this();

    m_a.push_back (new_a);

  }
   // ...
   std::vector<boost::shared_ptr <A> > m_a;
};

 

I would recommend reading the documentation at

http://www.boost.org/libs/smart_ptr/smart_ptr.htm

for more information.

 

________________________________

From: boost-users-bounces_at_[hidden] [mailto:boost-users-bounces_at_[hidden]] On Behalf Of Olivier Tournaire
Sent: Thursday, May 10, 2007 2:08 PM
To: boost-users_at_[hidden]
Subject: [Boost-users] Smart pointers

 

Hi all

Suppose I have two classes A and B like those ones :

class A
{
   // ...
   B *m_b;
};

class B
{
   // ...
   std::vector<A *> m_a;
};

m_b is used to know who is the parent of the object.

I would like to use smart pointers. How can I do this ?

Thanks in advance

-- 
Le temps des cerises reviendra. Dans l'immédiat, c'est le temps des noyaux. Courage.