====== C - C++ Callback functions ======

===== callback_function.hpp =====

<code cpp>
#pragma once

#include <string>

// Define a callback function based on a class method and call it with argument "output".
void use_callback_function(std::string output);
</code>

----

===== callback_function.cpp =====


<code cpp>
#include "callback_function.hpp"
#include <string>
#include <iostream>
#include <functional>


class MyClass
{
public:
  static void mystaticfunction(std::string str)
  {
    std::cout << str << std::endl;
  }


  void mymemberfunction(std::string str)
  {
    mystaticfunction(str);
  }
};


void test(std::string str, std::function<void(std::string)> callBack = nullptr)
{
  if (callBack)
  {
    callBack(str);
  }
}


void use_callback_function(std::string output)
{
  // Sample 1.
  test(output, MyClass::mystaticfunction);


  // Sample 2.
  MyClass myClass;
  auto callBack = [&myClass](std::string str)
  {
    myClass.mymemberfunction(str);
  };
  
  test(output, callBack);
}
</code>


----

===== References =====

https://en.cppreference.com/w/cpp/utility/functional/function