static pointer pointer_traits::pointer_to(see below r);
static pointer pointer_traits<T*>::pointer_to(see below r) noexcept;
Remarks: If element_type is cv void, the type of r is unspecified; otherwise, it is element_type&.
Returns: The first member function returns a pointer to r obtained by calling Ptr::pointer_to(r) through which indirection is valid; an instantiation of this function is ill-formed if Ptr does not have a matching pointer_to static member function. The second member function returns addressof(r).