shared_ptr additional Benefits of C + + fun

What are the additional benefits of shared_ptr (sp)? Destructors can execute normally even if they are converted to a base class.

Two classes known

Class foo{};

Class Bar:foo{public:~bar () {}};

First look at the situation without SP.

bar* obj = new bar ();

Delete obj;

This way Foo does not have a virtual destructor, and when the Foo object is deleted it is not called to the bar object's destructor.

If you use an SP, you can refactor normally.

sp<foo> obj = make_shared<bar> ();

shared_ptr additional Benefits of C + + fun