20 Memory management library [mem]

20.3 Smart pointers [smartptr]

20.3.2 Shared-ownership pointers [util.sharedptr] Class template shared_ptr [util.smartptr.shared] Destructor [util.smartptr.shared.dest]

  • If *this is empty or shares ownership with another shared_ptr instance (use_count() > 1), there are no side effects.
  • Otherwise, if *this owns an object p and a deleter d, d(p) is called.
  • Otherwise, *this owns a pointer p, and delete p is called.
[Note 1: 
Since the destruction of *this decreases the number of instances that share ownership with *this by one, after *this has been destroyed all shared_ptr instances that shared ownership with *this will report a use_count() that is one less than its previous value.
— end note]