<mp-units/framework/quantity_point.h>
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);