[indirect.comp.with.t]

template<class U>
  constexpr bool operator=(const indirect& lhs, const U& rhs) noexcept(noexcept(*lhs == rhs));

Mandates: The expression *lhs == rhs is well-formed and its result is convertible to bool.

Returns: If lhs is valueless, false; otherwise *lhs == rhs.

template<class U>
  constexpr synth-three-way-result<T, U>
    operator<=>(const indirect& lhs, const U& rhs);

Returns: If lhs is valueless, strong_ordering::less; otherwise synth-three-way(*lhs, rhs).

20 Memory management library [mem]