On Fri, Mar 30, 2012 at 08:14:18PM +0000, Christopher Pisz wrote:
Emil Dotchevski
writes: You could use weak_ptr to break shared_ptr cycles.
Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode
From boost docs: Q. Can an object create a weak_ptr to itself in its constructor?
A. No. A weak_ptr can only be created from a shared_ptr, and at object construction time no shared_ptr to the object exists yet.
This is the problem I cannot seem to easily overcome in both the case of the shared and weak ptr. It seems to work with a raw this pointer, but then I cannot achieve my goal.
If you have control over the places where the objects of the type are created, you might want to have two-phase initialization with a factory function to protect you from misuse. That is, something like (ignoring access and all): struct B { void init(weak_ptr<B> p) { self = p; } weak_ptr<B> self; }; struct D : B { }; shared_ptr<D> MakeD(..) { shared_ptr<D> ret = make_shared<D>(..); ret->init(ret); return ret; } -- Lars Viklund | zao@acc.umu.se