I have a Polynomial class which holds coefficients of a given polynomial.
One of its overloaded constructors is supposed to receive these coefficients via variable argument list.

template <class T>
Polynomial<T>::Polynomial(T FirstCoefficient, ...)
{
    va_list ArgumentPointer;
    va_start(ArgumentPointer, FirstCoefficient);
    T NextCoefficient = FirstCoefficient;
    std::vector<T> Coefficients;
    while (true)
    {
        Coefficients.push_back(NextCoefficient);
        NextCoefficient = va_arg(ArgumentPointer, T);
        if (/* did we retrieve all the arguments */) // How do I implement this?
        {
            break;
        }
    }
    m_Coefficients = Coefficients;
}

I know that we usually pass an extra parameter which tells the recipient method the total number of parameters, or we pass a sentimental ending parameter. But in order to keep thing short and clean, I don't prefer passing an extra parameter.

Is there any way of doing this without modifying the method signature in the example?