smaldMasterZivDestroy shared_ptr
Destroys the object. But, before, it may produce the following side effects depending on the value of member use_count:

If use_count is greater than 1 (i.e., the object is sharing ownership of its managed object with other shared_ptr objects): The use count of the other objects with which it shares ownership is decreased by 1.
If use_count is 1 (i.e., the object is the unique owner of the managed pointer): the object pointed by its owned pointer is deleted (if the shared_ptr object was constructed with a specefic deleter, this is called; Otherwise, the function uses operator delete).
If use_count is zero (i.e., the object is empty), this destructor has no side effects.



Если нигде не делали ptr2=ptr1, то при уничтожении ptr1 объект in deth,
в противном случае in deth при умирании ptr2. Но для параноиков есть unique_ptr.
Что такое in deth?