mp_units::operator*

template<
    std::derived_from<quantity> Q,
    typename Value>
requires (!Quantity<Value>) &&
            (!Reference<Value>) && detail::InvokeResultOf<quantity_spec, std::multiplies<>, rep, const Value&>
[[nodiscard]]
constexpr
QuantityOf<quantity_spec> auto
operator*(
    Q const& q,
    Value const& val);