// We show another definition of plus, as a function template.
// A rather direct and more down-to-earth approach.

#include <iostream>
#include <list>
#include <numeric>     // accumulate
#include <functional>  // binary_function

template<typename T> T plus_fn(T a, T b){
  return a + b;
}

int main(){
  std::list<double> lst;
  for(int i = 1; i <= 10; i++) lst.push_back(i);   // 1, 2, ..., 10

  // We must make an object which serves as a binary plus function: 
  double res = std::accumulate(lst.begin(), lst.end(), 0.0, plus_fn<double>);

  std::cout << "The plus accumulation is: " << res << std::endl;       // 55
}