79. Store only values and smart pointers in containers
Store objects of value in containers: Containers assume they contain value-like types, including value types (held directly), smart pointers, and iterators.
The most common use of containers is to store values held directly (e.g.,
set<string>). For containers of pointers: If the container owns the pointed-to objects, prefer a container of reference-counted smart pointers (e.g.,
list<shared_ptr<Widget> >); otherwise, a container of raw pointers (e.g.,
list<Widget*>) or of other pointer-like values such as iterators (e.g.,
list< vector<Widget>::iterator >) is fine.
auto_ptr. Objects of
auto_ptr<T> are not value-like because of their transfer-of-ownership ...