std::auto_ptr_ref - Man Page

auto_ptr_ref (_Tp1 *__p)

_Tp1 * _M_ptr

struct std::auto_ptr_ref< _Tp1 >"A wrapper class to provide auto_ptr with reference semantics. For example, an auto_ptr can be assigned (or constructed from) the result of a function which returns an auto_ptr by value.

All the auto_ptr_ref stuff should happen behind the scenes.