#include <iostream>
#include <vector>
#include <algorithm>
int main()
{
   using namespace std;
   vector<double> v;
   v.push_back(1.0);v.push_back(2.0);v.push_back(3.0);
   double prod=1.0;
   for_each(v.begin(),v.end(), [&prod] (double x) { prod *= x;});
   cout <<"product = "<< prod << endl;
}