template<class T>
struct remove_pointer;

If T has type “(possibly cv-qualified) pointer to T1” then the member typedef type denotes T1; otherwise, it denotes T.

template<class T>
struct add_pointer;

If T is a referenceable type ([defns.referenceable]) or a cv void type then the member typedef type denotes remove_reference_t<T>*; otherwise, type denotes T.