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From: dick.bridges_at_[hidden]
Date: 2002-09-30 16:38:49
1) There are circumstances where the 'creator' should stick around as long
as one or more 'creations' still exist (e.g., a [network] session that's
created various asynchronous conversations).
2) I haven't had time to check, but I think this is the
as-yet-not-but-soon-to-be-released implementation of intrusive pointers.
Interesting: search google for "intrusive pointer" (quotes not required).
I got five hits - all of the URLs start with www.boost.org/.
BTW: Really slick. Trying to figure out where to keep "THE POINTER" was
driving me nuts. I'd completely forgotten about intrusive pointers.
Thanks. A *LOT*.
Mark Storer
<mstorer_at_cardiff To: "'Boost-Users_at_[hidden]'" <Boost-Users_at_[hidden]>
.com> cc:
Subject: RE: [Boost-Users] Re: Use a shared_ptr as a 'backpointer'?
09/30/2002 09:36
AM
Please respond
to Boost-Users
I've got a comment and a question...
1) Couldn't the "backpointer" just be a constant reference? Backpointers,
in my mind, don't have anything to do with ownership, so a shared_ptr
woulnd't be appropriate.
2) shared_from_this?
I can't find that one in any of the headers or docs I
downloaded
with 1.28. I did find shared_count in (oddly enough) shared_count.hpp,
which looks like it would prevent two seperate shared_ptr's from causing a
double-delete... pretty slick, but I couldn't find any docs on it.
--Mark Storer
Software Engineer
Cardiff Software
#include <disclaimer>
typedef std::disclaimer<Cardiff> Discard;
-----Original Message-----
From: David Abrahams [mailto:yg-boost-users_at_[hidden]]
Sent: Sunday, September 29, 2002 4:12 PM
To: boost-users_at_[hidden]
Subject: [Boost-Users] Re: Use a shared_ptr as a 'backpointer'?
<dick.bridges_at_[hidden]> wrote in message
news:OF699D7956.EED22A4F-ON88256C43.00722AD0_at_tais.net...
> I run into situations where it's useful for an object to have a
> 'backpointer' to the object instance that created it (example below). Is
> there a pattern/idiom for doing this using shared_ptr? Or maybe I need
to
> re-think the idea of the backpointer in the first place?
>
class Bar;
class Foo
{
public:
Foo(shared_ptr<Bar>);
private:
shared_ptr<Bar> p;
};
class Bar : boost::shared_count
{
void doit()
{
new Foo(boost::shared_from_this(this)); // <<< new Foo(this)
obviously won't work.
}
};
HTH,
Dave
-- ----------------------------------------------------------- David Abrahams * Boost Consulting dave_at_[hidden] * http://www.boost-consulting.com Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe_at_[hidden]> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe_at_[hidden]> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
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