template<class Y> operator auto_ptr_ref<Y>() throw() { return auto_ptr_ref<Y>(release()); }
It is part of implementation of class auto_ptr in standard library.
What does this means to do?
Why there is an ‘auto_ptr_ref’ between ‘operator’ and ‘()’?
That is the conversion operator in action, casting from auto_ptr to auto_ptr_ref<Y>.