Am Wednesday 02 September 2009 18:55:03 schrieb Ryan Gallagher:
For using this, think about X lifetimes being managed by some other class (XManager). Think about another class A that isn't managed my XManager but needs to weakly reference some X instance.
Perhaps someone else can give a better, more realistic, example though, as even this one I wouldn't code this way.
I actually use that technique (without knowing the linked document). but I can't think of very many other use cases: My case handles a lot of objects that are not required to stay in memory but are also not supposed to be destroyed immediatly after they've been used, so they're not constantly re-created if they're used more than once (loaded back from disk in my case). class cache_element : public intrusive::slist_base_hook<>{ ... private: shared_ptr<cache_element> this_; ... }; class object : cache_element{ ... }; the objects are only referenced by weak_ptr's throughout the code, and loaded back from disk if weak_ptr::lock() fails. so the only reference keeping the object in memory is an object cache, which fills cache_element::this_ on first access and removes the element from the list of cached elements when the cache overflows, using a disposer like that: struct disposer{ void operator()(cache_element *element){ shared_ptr<cache_element> ptr; ptr.swap(element->this_); } };