// Any number of arguments to sum_of_squares()
#include <iostream>
#include <cmath>
using std::cout;
using std::pow;

auto sum_of_squares() {return 0; }// end of recursion

template <typename T,typename ...Ts>
auto sum_of_squares(T first, Ts ... rest)  
{ 
  return pow(first,2) + sum_of_squares(rest ...);   // recursive 
}

int main()
{
  cout<<sum_of_squares(1,2)<<"\n"; 
  cout<<sum_of_squares(1,2,3,4,5)<<"\n"; 
  cout<<sum_of_squares(1.1,2.2,3.3)<<"\n";  
  cout<<sum_of_squares(1,2.1,3.1)<<"\n";   
}