weak_ptr to break cyclic reference

[Pallav singh]

Hi All

How to use weak_ptr to break cyclic reference here ?

#include <iostream>
#include <boost/smart_ptr.hpp>
using namespace std;

struct Dad;
struct Child;

typedef boost::shared_ptr<Dad> DadPtr;
typedef boost::shared_ptr<Child> ChildPtr;


struct Dad
{
ChildPtr myBoy;
};

struct CChild
{
DadPtr myDad;
};

// a "thing" that holds a smart pointer to another "thing":
DadPtr parent(new DadPtr);
ChildPtr child(new ChildPtr);

// deliberately create a circular reference:
parent->myBoy = child;
child->myDad = dad;

Thanks
Pallav Singh

 

[Marcel Müller]

Hi,

// a "thing" that holds a smart pointer to another "thing":
DadPtr parent(new DadPtr);
ChildPtr child(new ChildPtr);

// deliberately create a circular reference:
parent->myBoy = child;
child->myDad = dad;

If your child objects have an existence dependency on their parents you
can safely use a weak pointer from child to parent.


Marcel