FAQ 28.07 Can auto_ptrT simplify ownership problems with containers of pointers?

FAQ 28.07 Can auto_ptr<T> simplify ownership problems with containers of pointers?

No, auto_ptr<T> usually makes things worse!

Generally speaking, auto_ptr<T> should not be used inside container classes. For example, if a List of Fred pointers is desired, it is usually bad to use a List<auto_ptr<Fred> >. The reason is that copying an auto_ptr<T> makes changes to the original, in addition to the obvious changes to the copy. In particular, the ownership of the referent is transferred to the copy, so the original will be NULL. For example, if someone retrieved a copy of an element in the List, that would copy the auto_ptr<T>, which would transfer ownership of the referent to the copy and the auto_ptr<T> in the List would be NULL.