mp_units::quantity::operator%=

template<
    auto R2,
    typename Rep2>
requires (!treat_as_floating_point<rep>) && (implicitly_convertible(get_quantity_spec(R2), quantity_spec)) &&
            detail::ValuePreservingConversion<get_unit(R2), Rep2, unit, rep> && requires(rep& a, const Rep2 b) {
              { a %= b } ‐> std::same_as<rep&>;
            }
constexpr
quantity&
operator%=(quantity<R2, Rep2> const& other) &;