Frank Mori Hess wrote:
Nat Goodspeed wrote:
I want my visitor to detect a bound boost::shared_ptr<anything> and pass the shared_ptr to my new slot_type object's track() method.
Frank, couldn't the Signals2 library incorporate that logic itself?
I don't view the "dynamically replace bound shared_ptr with weak_ptr in incoming bind functor" idea as viable.
Sigh, yeah -- that would seem to call for a whole new boost::bind() feature supporting copy-with-transformation.
But if you mean the general feature of searching for some base class during connect and automatically tracking those objects, that might get added in the future. I would do it strictly as an optional extension though, in separate headers and only using the library's existing public interfaces. It would add a free function findable by ADL that would look for the trackable base class when connecting, something like:
class shared_trackable: public enable_shared_from_this
{};
If I understand correctly, we expect the coder to pass to boost::bind() a plain pointer, a reference or a weak_ptr to a shared_trackable subclass instance. None of those will artificially prolong the life of that instance. However, using enable_shared_from_this lets your visitor obtain a shared_ptr to pass to slot_type::track(). Yes? It's still the case that if the coder passes to boost::bind() an actual shared_ptr to the shared_trackable subclass instance, the slot_type::track() mechanism becomes irrelevant because the object won't die. That might warrant a note in the documentation for this feature.