#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;
typedef double single;
class SinglePersonProblem : protected exception
{
public:
   SinglePersonProblem(string reason = "The biggest problem is that you are Single") throw():m_reason(reason){};
   ~SinglePersonProblem()throw(){};
   const char* what() const throw(){return m_reason.c_str();};
private:
   mutable string m_reason;
};
class Person
{
private:
   static const single MagicianStartAge;
   single single_age;
   bool isMagician;
   void AddAge(single age);
public:
   explicit Person(single age = 21);
   Person operator ++(int);
   Person& operator ++();
   Person& operator + (single age);
   double operator+ (const Person& anotherSinglePerson);
   double operator* (const Person& anotherSinglePerson);
   bool operator==(const Person& anotherSinglePerson) const;
   bool operator!=(const Person& anotherSinglePerson) const;
};
const single Person::MagicianStartAge = 30;
Person::Person(single age): single_age(0), isMagician(false)
{
   if (age < 0)
   {
   SinglePersonProblem problem("An \"anti-single\" person should be a dead person");
   throw problem;
   }
   AddAge(age);
}
Person Person::operator ++(int)
{
   Person earlierPerson(single_age);
   AddAge(1);
   return earlierPerson;
}
Person& Person::operator ++()
{
   AddAge(1);
   return *this;
}
Person& Person::operator + (single age)
{
   AddAge(age);
   return *this;
}
double Person::operator+ (const Person& anotherSinglePerson)
{
   SinglePersonProblem problem("Two Single Person all together are still Two Single Person! It will never return a double!");
   throw problem;
}
double Person::operator* (const Person& anotherSinglePerson)
{
   SinglePersonProblem problem("Two Single Person multiple each other are still Two Single Person! It will never return a double!");
   throw problem;
}
bool Person::operator==(const Person& anotherSinglePerson) const
{
   bool ret = false;
   if (NULL != &anotherSinglePerson)
   if (this->single_age == anotherSinglePerson.single_age)
   {
   cout << "Good, you got a buddy now!" << endl;
   ret = true;
   }
   return ret;
}
bool Person::operator!=(const Person& anotherSinglePerson) const
{
   return !(*this == anotherSinglePerson);
}
void Person::AddAge(single age)
{
   if (age < 0)
   {
   SinglePersonProblem problem("Forget about that! Don't try to decrease your single age!");
   throw problem;
   }
   single_age += age;
   if (single_age >= MagicianStartAge && !isMagician)
   {
   isMagician = true;
   cout << "Congratulations! You're a " << single_age << "-year-old Magician Now!" << endl;
   }
}
int _tmain(int argc, _TCHAR* argv[])
{
   try
   {
   Person a, b, c, d(25);
   d++;
   a*b;
   }
   catch (SinglePersonProblem& e)
   {
   cout<< "Exception: " << e.what() << endl;
   }
   return 0;
}

判断是不是魔法师的程序？
没有很仔细看