operator引用貌似本对象@_@

    friend ostream& operator<<(ostream& os,const 类名 &类定义的){os<<类定义的.成员<<endl;return os;}
    friend istream& operator>>(istream &is,类名 &类定义的){is>>类定义的.成员;return is;}
    TT &operator++()
    TT operator++(int)//再定义一个类定义的
    TT &operator--()
    TT &operator--(int)//在定义一个类定义的

友出引运<<出引os常类引用

友入引运>>入引is类引用

后置无引用，多int多定义一个

class Time

{

private :

     int h,m,s;

public :

     Time():h(0),m(0),s(0) {}

     friend ostream& operator<<(ostream& os, const Time &a)

     {

         if (a.h>=0&&a.h<24&&a.m>=0&&a.m<60&&a.s>=0&&a.s<60)

             os<<setw(2)<<setfill( '0' )<<a.h<< ":" <<setw(2)<<setfill( '0' )<<a.m<< ":" <<setw(2)<<setfill( '0' )<<a.s;

         else

             os<< "error!!!" ;

         return os;

     }

     friend istream& operator>>(istream& is,Time& a)

     {

         is >> a.h>>a.m>>a.s;

         return is;

     }

     Time& operator--()

     {

         if (h>=0&&h<24&&m>=0&&m<60&&s>=0&&s<60)

         {

             --s;

             if (s<0)

             {

                 s+=60;

                 --m;

             }

             if (m<0)

             {

                 m+=60;

                 --h;

             }

             if (h<0)

                 h+=24;

         }

         return * this ;

     }

     Time operator--( int )

     {

         Time q=(* this );

         if (h>=0&&h<24&&m>=0&&m<60&&s>=0&&s<60)

         {

             --s;

             if (s<0)

             {

                 s+=60;

                 --m;

             }

             if (m<0)

             {

                 m+=60;

                 --h;

             }

             if (h<0)

                 h+=24;

         }

         return q;

     }

     Time& operator++()

     {

         if (h>=0&&h<24&&m>=0&&m<60&&s>=0&&s<60)

         {

             ++s;

             if (s>=60)

             {

                 s-=60;

                 ++m;

             }

             if (m>=60)

             {

                 m-=60;

                 ++h;

             }

             if (h>=24)

                 h-=24;

         }

         return * this ;

     }

 

     Time operator++( int )

     {

         Time q=(* this );

         if (h>=0&&h<24&&m>=0&&m<60&&s>=0&&s<60)

         {

             s++;

             if (s>=60)

             {

                 s-=60;

                 m++;

             }

             if (m>=60)

             {

                 m-=60;

                 h++;

             }

             if (h>=24)

                 h-=24;

         }

         return q;

     }

};

转载于:https://www.cnblogs.com/TogetherLaugh/p/6582342.html