/////////////////////////////////////////////////////////////////////////////////
// StructWithFunctions.cpp - demonstrates ideas used to build class instances  //  
//                                                                             //
// Jim Fawcett, Summer Short Course, Su2016                                    //
/////////////////////////////////////////////////////////////////////////////////
/*
 * Found in: Handouts\ShortCourse\Repository\GettingStartedExamples
 *
 * This code is written in C Language style, but won't compile as a 
 * C program because we are using C++ strings and streams
 *
 */

#include <string>
#include <iostream>

// forward struct declaration 

struct Swf;

// function pointer declarations

typedef void(*initializerType)(Swf* pThis, const std::string& msg);
typedef void(*terminatorType)(Swf* pThis);
typedef void(*sayType)(Swf* pThis);

struct Swf
{
  // struct holds function pointers

  static initializerType initializer;  // stored in static memory with code
  static terminatorType terminator;    //    "
  static sayType say;                  //    "

  // struct holds data

  std::string msg_;                    // stored with each instance in stack or heap
};

// definition of static data - reserves static memory to hold pointer values

initializerType Swf::initializer;
terminatorType Swf::terminator;
sayType Swf::say;

//----< constructor >------------------------------------------------

void initializer(Swf* pThis, const std::string& msg)
{
  pThis->msg_ = msg;
}
//----< destructor >-------------------------------------------------

void terminator(Swf* pThis)
{
  pThis->msg_ = "";
}
//----< member function >--------------------------------------------

void say(Swf* pThis)
{
  std::cout << "\n  " << pThis->msg_.c_str();
}
//----< test stub >--------------------------------------------------

int main()
{
  Swf::initializer = initializer;
  Swf::terminator = terminator;
  Swf::say = say;

  Swf s1;
  s1.initializer(&s1, "Hi, I'm s1");
  s1.say(&s1);
  s1.terminator(&s1);

  Swf s2;
  s2.initializer(&s2, "Hello, I'm s2");
  s2.say(&s2);
  s2.terminator(&s2);

  std::cout << "\n\n";
}