mp_units::quantity_point::in

template<
    RepresentationOf<quantity_spec> ToRep,
    UnitOf<quantity_spec> ToU,
    RoundingPolicy Policy>
requires std::constructible_from<ToRep, rep> && detail::ExplicitlyCastable<unit, ToU{}, ToRep> &&
             detail::ValidRoundingPolicyFor<Policy, rep, ToRep>
[[nodiscard]]
constexpr
QuantityPointOf<quantity_spec> auto
in(
    ToU,
    Policy policy) const;