mp_units::operator‐

template<
    PointOrigin PO1,
    std::derived_from<quantity_point> QP>
requires QuantityPointOf<quantity_point, PO1{}> &&
             ReferenceOf<MP_UNITS_NONCONST_TYPE(reference), PO1::_quantity_spec_>
[[nodiscard]]
constexpr
Quantity auto
operator‐(
    PO1 po,
    QP const& qp);

template<
    std::derived_from<quantity> Q,
    RepresentationOf<quantity_spec> Value>
requires detail::DimensionlessOne<Q::reference> &&
             detail::InvokeResultOf<quantity_spec, std::minus<>, Rep, const Value&>
[[nodiscard]]
constexpr
Quantity auto
operator‐(
    Q const& lhs,
    Value const& rhs);

template<
    std::derived_from<quantity_point> QP,
    QuantityPointOf<absolute_point_origin> QP2>
[[nodiscard]]
constexpr
Quantity auto
operator‐(
    QP const& lhs,
    QP2 const& rhs)
requires requires { lhs.quantity_ref_from(point_origin) ‐ rhs.quantity_ref_from(QP2::point_origin); };

template<
    std::derived_from<quantity_point> QP,
    PointOrigin PO2>
requires QuantityPointOf<quantity_point, PO2{}> &&
             ReferenceOf<MP_UNITS_NONCONST_TYPE(reference), PO2::_quantity_spec_>
[[nodiscard]]
constexpr
Quantity auto
operator‐(
    QP const& qp,
    PO2 po);

template<
    std::derived_from<quantity> Q,
    RepresentationOf<quantity_spec> Value>
requires detail::DimensionlessOne<Q::reference> &&
             detail::InvokeResultOf<quantity_spec, std::minus<>, Rep, const Value&>
[[nodiscard]]
constexpr
Quantity auto
operator‐(
    Value const& lhs,
    Q const& rhs);

template<
    std::derived_from<quantity> Q,
    auto R2,
    typename Rep2>
requires detail::CommonlyInvocableQuantities<std::minus<>, quantity, quantity<R2, Rep2>>
[[nodiscard]]
constexpr
Quantity auto
operator‐(
    Q const& lhs,
    quantity<R2, Rep2> const& rhs);

template<
    std::derived_from<quantity_point> QP,
    ReferenceOf<PO._quantity_spec_> auto R2,
    typename Rep2>
[[nodiscard]]
constexpr
QuantityPoint auto
operator‐(
    QP const& qp,
    quantity<R2, Rep2> const& q)
requires requires { qp.quantity_ref_from(PO) ‐ q; };