Re: vector problem

From:

Dan Bloomquist <public21@lakeweb.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Tue, 18 Mar 2008 23:23:00 GMT

Message-ID:

<o9YDj.117$NU2.107@news01.roc.ny>

Giovanni Dicanio wrote:

"Dan Bloomquist" <public21@lakeweb.com> ha scritto nel messaggio
news:EKVDj.98$Cn4.37@news02.roc.ny...

I've seen std::vector copy an object more than once while it is working,
as I recall. It doesn't matter as it knows what it is doing. As long as
that is what you mean by 'doesn't work'.

I think that this is a reson why we should use std::vector storing
shared_ptr (smart pointers) of class instances, especially for "big"
objects, so we can avoid expensive deep-copies.

Hay, I got off my duff. I just ran into a situation where I may or may
not want to use a returned object. And since it is a not a member of
another object, it has no persistence.

So:
typedef boost::shared_ptr<CXML> spXML;
  ...
//member that creates xml

spCXML ColumnHeaders::LoadUserXML( )
{
    //So, instead of
    //CXML xml;

    spCXML pXml( new CXML );

    //I do this so intelesense works,
    // a problem using Boost I've seen before.
    CXML& xml= *pXml;
....
    return pXml;
}

Now I can grab the object if I'd like, then forget it, or just forget it
if I don't need it!

Thanks Giovanni.

Best, Dan.