#include <iostream>

class UnluckyNumber : public std::exception
{
public:
  UnluckyNumber(const char* msg) { mMsg = msg; }
  virtual const char* what() const throw() { return mMsg; }

private:
  const char* mMsg;
};

class Cow
{
public:
  Cow() { std::cout << "Moo!" << std::endl; }
  ~Cow() { std::cout << "x_x" << std::endl; }
};


int pickANumber(int n)
{
  std::cout << "entering pickANumber()" << std::endl;
  Cow c;
  if(n % 2 == 0){
    throw UnluckyNumber("That is not a good number.");
  }
  if(n % 7 == 0){
    throw UnluckyNumber("That's a terrible number!");
  }

  std::cout << "exiting pickANumber()" << std::endl;
  return n;
}


int main(int argc, char* argv[])
{
  // 1
  // Nothing goes wrong here
  // Note that the Cow is destroyed as pickANumber() exits 
  try {
    std::cout << "The first number is..." << pickANumber(5) << std::endl;
  }
  catch (UnluckyNumber& e) { }

  // 2
  // Exception!
  // Note that the function exit string is never printed, but the Cow is
  // still destroyed when the stack is unwound due to the exception.
  try {
    std::cout << "The second number is: " << pickANumber(6) << std::endl;
  }
  // We can catch *all* exceptions
  catch (std::exception& e){
    std::cout << "some other error: " << e.what() << std::endl;
  }

  // 3
  try {
    std::cout << "The third number is: " << pickANumber(21) << std::endl;
  }
  // Or just catch UnluckyNumber exceptions
  catch (UnluckyNumber& e) {
    std::cout << "something went horribly wrong: " << e.what() << std::endl;
  }

  return(0);
}