shared_pointer

Aliasing

shared_pointer can share ownership with another pointer, but it actually points to a different object.
That is, the owned object and the pointed object are not the same thing.

//aliasing constructortemplate<class Y>shared_ptr(const shared_ptr<Y>& r, element_type* ptr) noexcept;

class Foo {public:Foo(int value) : m_data { value} { }int m_data;};auto foo { make_shared<Foo>(42) };auto aliasing { shared_ptr<int> { foo, &foo->m_data } };//aliasing and foo share ownership of the Foo object, but aliasing points to its member variables