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Re: pointers to object questions


Hi Eljay,

Thanks for the help, and sorry for posting an
off-topic question.
The problem that I was having was related to your 3rd
advice. The live span of theData was too short, and I
fixed it by adding "Data * theData;" to the Data.h
file, and then making the Sender constructor like 

Sender::Sender( Connector * newConnector )
{
	theConnector = newConnector;
	theData = new Data( newConnector );
}

Also, thanks for the Smart Pointers webpage. I'm going
to study it because I still have a lot to learn :-)

Andre


--- Eljay Love-Jensen <eljay@adobe.com> wrote:
> Hi Andre,
> 
> Your question is off-topic for this forum, as it is
> not a GCC related 
> question.  Rather, it is a C++ related question.
> 
> Given that, here's my advice.
> 
> #1...
> Is NULL allowed to be passed into
> Sender::Sender(Connector* newConnector)?
> 
> If not, then I recommend you change it to
> Sender::Sender(Connector& 
> newConnector).  That also means changing Sender's
> member variable from 
> "Connector* theConnector" to "Connector&
> theConnector", and doing the 
> initialization in the Sender::Sender's
> initialization list.
> 
> Note:  if "Connector" is the root of a hierarchy of
> different kinds of 
> connectors, you may run into some issues for
> non-const reference 
> passing.  In my opinion, it's worth taking the time
> to resolve those issues.
> 
> #2...
> Who owns theConnector?
> 
> Is ownership being passed in?  No, not really.  But
> if it were, I'd say you 
> should pass in the Connector object via
> auto_ptr<Connector>, which 
> indicates a transfer of ownership.
> 
> Is ownership being shared (or distributed)?  Yes,
> sort of.  I recommend 
> looking at BOOST Smart 
> Pointers: 
> <http://www.boost.org/libs/smart_ptr/smart_ptr.htm>.
> 
> #3...
> The answer to "What could be wrong" ... you should
> provide a compilable 
> small example that demonstrates the problem.  My own
> toy example doesn't 
> exhibit the problem.  NOTE:  the lifespan of Data
> theData object expires 
> quite quickly:  at the end of the Sender
> constructor.
> 
> HTH,
> --Eljay
> 
> 



		
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