#include <stdarg.h>

template < int n >
class Vec
{
private:
    float e[n];
public:
    Vec(float e0, …) {
        va_list params;
        va_start(params, e0);
        e[0] = e0;
        for (int j = 0; j < n; ++j) {
            e[j] = (float)va_arg(params, double);
        }
        va_end(params);
    }
};