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