関連ワード:  c++ pass shared pointer by reference    c++ pass shared pointer by reference or value    c++ pass shared_ptr by reference or value    c++ pass shared_ptr by reference    c++ pass smart pointer by reference    c++ pass smart pointer by reference or value    c++ return shared_ptr by reference or value    c++ return reference to shared_ptr    c++ pass shared pointer by const reference    c++ should i pass shared_ptr by reference