1.普通类

//class headclass complex//class body {}{public:    complex(double r=0, double i)        :re(r), im(i)    {}//构造函数    complex& operator += (const complex&);    double real() const { return re; }//获取实部的函数    double imag() const { return im; }//获取虚部的函数private:    double re, im;    friend complex& __doapl(complex*, const complex&);};

2.模板类

//导入模板template
     
      class complex{public:    complex(T r = 0, T i = 0)        :re(r), im(i)    {}    complex& operator += (const complex&);    T real() const { return re; }    T imag() const { return im; }private:    T re, im;    friend complex& __doapl(complex*, const complex&);};//调用时需要制定类型<>//{//    complex
      
        c1(2.5, 1.5);//    complex
       
         c2(2, 6);//}