#include <algorithm> 
#include <functional> 
#include <vector> 
#include <iostream> 

class divide_by 
  : public std::binary_function<int, int, int> 
{ 
public: 
  int operator()(int n, int div) const 
  { 
    return n / div; 
  } 
}; 

int main() 
{ 
  std::vector<int> numbers; 
  numbers.push_back(10); 
  numbers.push_back(20); 
  numbers.push_back(30); 

  std::transform(numbers.begin(), numbers.end(), numbers.begin(), 
    std::bind2nd(divide_by(), 2)); 

  for (std::vector<int>::iterator it = numbers.begin(); 
    it != numbers.end(); ++it) 
    std::cout << *it << std::endl; 
}