// A reproduction of the for-each algorithm, and a sample use on a C-style array.

#include <iostream>
#include <string>

// A possible definition of the for_each function template. 
template <typename InputIt, typename Function>
Function for_each(InputIt first, InputIt last, Function f){
  while (first != last) f(*first++);      // Notice the use of operator() on f 
  return f;
}

void print_element(const int &i){
  std::cout << i << std::endl;
}

int main(){
  int a[] = {7,9,8,1,-1};

  // The two first parameters are iterators:
  for_each(a, a+3, print_element);  // 7, 9, 8

  std::cout << std::endl;

  // Same with a lambda expression.
  for_each(a, a+3, [](const int &el){std::cout << el << std::endl;}); // 7, 9, 8
}