add_lvalue_reference_t<T> operator*() const;
Requires: get() != nullptr.
Returns: *get().
pointer operator->() const noexcept;
Requires: get() != nullptr.
Returns: get().
Note: use typically requires that T be a complete type.
Returns: The stored pointer.
deleter_type& get_deleter() noexcept;
const deleter_type& get_deleter() const noexcept;
Returns: A reference to the stored deleter.
explicit operator bool() const noexcept;
Returns: get() != nullptr.