Dear Jeff, 
Thanx for your quick reply.  FUrther to the same question, 
can you please explain:
   > There is also weak_ptr originally intended to break cycles which may be
of use to you.
  - the meaning of breaking cycles, and how it can help in this situation.

It is said that a weak ptr doesn't increment the refcount.  That means there
is a possibility of the pointee object being deleted, while a weak ptr is
holding a reference of it.  So, in my understanding, if i return a weak-ptr
to the clients of my object, then I will be able to delete my object at time
of my choosing inspite of how many number of weak-ptr references the clients
may have. But after this, the weak-ptr reference becomes invalid. Am I
right?

regards,
RV

Jeff Flinn wrote:
> 
> rv_nath wrote:
>> Hi forum members,
>> 
>> I want to use boost's shared_ptr class for the connection pool class that
>> i
>> am writing.  However, i have a requirement to delete the connection
>> object
>> (which is going to be the shared-ptr) explicitly based on certain checks
>> like validity and expiry etc.  If I store the shared_ptr, I want to know
>> how
>> to delete this explicitly from the stl container.  
>> 
>> According to my understanding shared_ptrs cannot be 'delete'd.  So, how
>> to
>> achieve this...?
> 
> shared_ptr's CAN be deleted(or reset to NULL), you can NOT directly 
> delete the shared item that the shared_ptr is managing. When the last 
> shared_ptr referencing the shared item is deleted(or reset) it will 
> delete the shared item. There is also weak_ptr originally intended to 
> break cycles which may be of use to you. Otherwise your design will need 
> to communicate when to take appropriate actions.
> 
> Jeff
> 
> _______________________________________________
> Boost-users mailing list
> Boost-users@lists.boost.org
> http://lists.boost.org/mailman/listinfo.cgi/boost-users
> 
> 

-- 
View this message in context: http://old.nabble.com/how-to-delete-references-to-objects-from-a-container...-tp26710061p26712344.html
Sent from the Boost - Users mailing list archive at Nabble.com.

 So, in my understanding, if i return a weak-ptr to the clients of my object, then I will be able to delete my object at time of my choosing inspite of how many number of weak-ptr references the clients may have. But after this, the weak-ptr reference becomes invalid. Am I right?

You never can *delete* an object (in the sense of invoking delete() operator), which is accessed through shared_ptr. It can be deleted by shared_ptr's deleter only. If you return to your clients weak_ptr's to a "living" object, they probably will lock() that weak_ptr in order to access the object, and the object will be deleted only after all the clients dispose their weak/shared ptrs.