递增运算符重载

#include <iostream>

class Person
{
public:
   void age_set(int age)
   {
      m_age = age;
   }

   int age_get()
   {
       return m_age;
   }

   /* 前置++ */
   Person &operator++()
   {
      ++m_age;
      return *this;
   }

   /* 后置++ */
   Person operator++(int)
   {
      Person p = *this;
      m_age++;
      return p;
   }

private:
   int m_age;
};

int main()
{
   Person p;
   p.age_set(10);

   std::cout << (++p).age_get() << std::endl; 
   std::cout << (p++).age_get() << std::endl; 
   std::cout << p.age_get() << std::endl; 

   return 0;
}

$ ./a.out          
11
11
12