{
        if (m1.unitOfMeasure() == m2.unitOfMeasure()) {
            return m1.amount() <= m2.amount();
        } else if (Quantity::conversionType
                   == Quantity::BaseUnitOfMeasureConversion) {
            Quantity tmp1 = m1;
            convertToBase(tmp1);
            Quantity tmp2 = m2;
            convertToBase(tmp2);
            return tmp1 <= tmp2;
        } else if (Quantity::conversionType == Quantity::AutomatedConversion) {
            Quantity tmp = m2;
            convertTo(tmp, m1.unitOfMeasure());
            return m1 <= tmp;
        } else {
            QL_FAIL("unitOfMeasure mismatch and no conversion specified");
        }
    }