receiver<T>() (1) (defaulted) receiver<T>(const receiver<T> & x) (2) receiver<T>(receiver<T> &&) (3) (defaulted) (1) receiver<T>() (defaulted) (2) receiver<T>(const receiver<T> & x) MISSING Parameters const receiver<T> & x (3) receiver<T>(receiver<T> &&) (defaulted) Parameters receiver<T> && unnamed