TypedefFunctions.cc

#include <iostream>
#include <functional>

typedef std::function<int(int)> Addable;

int addem(int start) {
  std::cout << "Add: " << start << std::endl;
  return start + 10;
}

int subem(int start) {
  std::cout << "Sub: " << start << std::endl;
  return start - 5;
}

/* This is somewhat silly and pointless, but it really 
 * does help me visualize how the new functional programming
 * features in C++ work.
 */

int main() {
  Addable addable = addem;
  int start = 5;

  start = addable(5);
  for(int i = 0; i < 20; i++) {
    addable = (i % 2 == 0) ? addem : subem;
    start = addable(start);
  }
  
  std::cout << "Done: " << start << std::endl;
}