mp_units::operator*

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