Safe ParseInt C++

    template <typename T> int SignBit(T val) {
        return (T(0) < val) - (val < T(0));
    }

    template <typename T>
    bool ParseInt(const AuString& in, T& out)
    {
        T res = 0;
        T sign = 1;
        out = 0;

        auto itr = in.begin();

        if constexpr (std::is_same<T, AuSInt>::value)
        {
            if (itr != in.end())
            {
                if (*itr == '-')
                {
                    itr++;
                    sign = -1;
                }
            }
        }

        for (;
             (itr != in.end()) &&
             (*itr != '\0');
             itr++)
        {
            auto c = *itr;

            if ((c < '0') || (c > '9')) return false;

            auto old = res;

            res *= 10;
            res += static_cast<AuUInt>(*itr) - static_cast<AuUInt>('0');

            if constexpr (std::is_same<T, AuUInt>::value)
            {
                if (old > res)
                {
                    LogDbg("Unsigned integer overflow");
                    return false;
                }
            }
            else if constexpr (std::is_same<T, AuSInt>::value)
            {
                if (SignBit(old) != SignBit(res))
                {
                    LogDbg("Signed integer overflow");
                    return false;
                }
            }
        }

        out = res * sign;
        return true;
    }

    template <typename T>
    bool ParseUInt(const AuString& in, T& out)
    {
        auto temp = AuUInt{};
        out = 0;

        if (!ParseInt<AuUInt>(in, temp)) return false;

        if (temp > std::numeric_limits<T>::max()) return false;

        out = temp;
        return true;
    }

    template <typename T>
    bool ParseSInt(const AuString& in, T& out)
    {
        auto temp = AuSInt{};
        out = 0;

        if (!ParseInt<AuSInt>(in, temp)) return false;

        if (temp > std::numeric_limits<T>::max()) return false;
        if (temp < std::numeric_limits<T>::min()) return false;

        out = temp;
        return true;
    }