How to force user to give either D or 0 parameters in class constructor with template

This question already has an answer here:

• Fixed Length Variadic Parameter Packs in C++11 2 answers

I'm making a class that makes use of a C-array of type, which is of size D, with mathematicals operations.

The class can be summed as follows :

template <typename T, unsigned char D>
class point
{
private:
    T p [D];

public:

    typedef T value_type;
    static const unsigned char dimension = D;

    point (const T...); //Here I put variadic argument but it wont do.
 };

I would like to enforce the user to use either 0 parameters (point()) or D (point(2.f,5.f)).

So that's my question : Is there a way to force the user at compile-time to declare as much parameters as he asked for ? And is it possible to enable him to use the same constructor as a default constructor ?

Thank you for reading.