TEST(Summation, ConvertSpecialToDecimal) {
    constexpr double infinity = std::numeric_limits<double>::infinity();
    DoubleDoubleSummation sum;
    
    sum.addDouble(infinity);    
    ASSERT_EQUALS(infinity, sum.getDouble()); // ok
    ASSERT_TRUE(sum.getDecimal().isInfinite()); // <-- fail here, it's nan
    ASSERT_FALSE(sum.getDecimal().isNaN()); // <!-- fail here, it is actually nan
    
    sum.addDouble(1); // now once we add something to sum, everything is ok
    ASSERT_EQUALS(infinity, sum.getDouble()); // ok, still infinity
    ASSERT_TRUE(sum.getDecimal().isInfinite()); // ok, now it's infinity
    ASSERT_FALSE(sum.getDecimal().isNaN()); // ok, not nan
}