On 06/16/2005 06:38 AM, Peter Dimov wrote: [snip]
tr1::shared_ptr as well. It has been developed in response to Eric Niebler's scenario where the roots that form cycles are known to the programmer. (He ended up not using it, though :-) )
It's possible to combine the two approaches and perhaps provide a default enable_tracking that does a memory scan as in sp_collector. I think that in most typical cyclic shared_ptr situations the problematic roots are known in advance, though, so a reset_and_collect-type solution may be enough.
But if the problematic roots are known in advance, why doesn't the programmer simply use weak_ptr's to them? I guess it's because the programmer doesn't know he's connecting to a problematic root, although he knows what they are. I guess he doesn't want to store the identity of the problematic roots in some global data structure and check each time he makes a connection. Eric, is that about right?