AsyncFunctionExample

#include <iostream>
#include <functional>
#include <atomic>
#include <iostream>
#include <future>

class AsyncFunctionExample
{
std::atomic<bool> var_1;
std::atomic<bool> var_2;
std::atomic<bool> is_finished;
std::function<void(AsyncFunctionExample&)> current_function;

void Function1()
{
  if(!var_1 && !var_2)
  {
    var_1 = true;
    current_function = &AsyncFunctionExample::Function2;
  }
  else if(var_1 && var_2)
  {
    is_finished = true;
    current_function = nullptr;
  }
}

void Function2()
{
  if(var_1 && !var_2)
  {
    var_2 = true;
    current_function = &AsyncFunctionExample::Function1;
  }
}

void Test1()
{
  // this works
  var_1 = false;
  var_2 = false;
  is_finished = false;
  current_function = &AsyncFunctionExample::Function1;
  while(current_function != nullptr)
    current_function(*this);
}

void Test2()
{
  // this works
  var_1 = false;
  var_2 = false;
  is_finished = false;
  current_function = &AsyncFunctionExample::Function1;
  while(current_function != nullptr)
  {
    const std::future<void> function_future = std::async([&](){current_function(*this); });
    function_future.wait();
  }
}

void Test3()
{
  var_1 = false;
  var_2 = false;
  is_finished = false;
  current_function = &AsyncFunctionExample::Function1;
  while(current_function != nullptr)
  {
    const std::future<void> function_future = std::async(current_function, *this);
    function_future.wait();
  }
}

 public:
void Run()
{
  Test1();
  if(!is_finished)
    std::cerr << "Test 1 fails." << "\r\n";
  else
    std::cerr << "Test 1 succeeds." << "\r\n";

  Test2();
  if(!is_finished)
    std::cerr << "Test 2 fails." << "\r\n";
  else
    std::cerr << "Test 2 succeeds." << "\r\n";

  Test3();
  if(!is_finished)
    std::cerr << "Test 3 fails." << "\r\n";
  else
    std::cerr << "Test 3 succeeds." << "\r\n";
}
};

int main() {
  AsyncFunctionExample afe;
  afe.Run();
  return 0;
}