1.Class without point （comples）博览网~

OX01 首先还是把实现comples类的代码贴过来..

#ifndef __MYCOMPLEX__

#define __MYCOMPLEX__   

class complex; 

complex& __doapl (complex* ths, const complex& r);

class complex{

public:

 complex (double r = 0, double i = 0): re (r), im (i) { } 

 complex& operator += (const complex&);

 double real ()  const  { return re; } 

 double imag () const { return im; }

private:

 double re, im;

         friend complex& __doapl (complex *, const complex&); 

};

include

inline ostream&

operator << (ostream& os , const comples& r)

{

 return os << "("<

}

inline complex&

__doapl (complex* ths, const complex& r)

{

 ths->re += r.re; ths->im += r.im; 

 return *ths;

}

inline complex&

complex::operator += (const complex& r)

{ 

 return __doapl (this, r);               

}

 inline double

imag (const complex& x){

 return x.imag ();

}

inline double

real (const complex& x)

{

 return x.real ();

}

inline complex                      

operator + (const complex& x, const complex& y)

{ 

 return complex (real (x) + real (y), imag (x) + imag (y));

}

inline complex

operator + (const complex& x, double y)

{

 return complex (real (x) + y, imag (x));

}

inline complex

operator + (double x, const complex& y)

{

 return complex (x + real (y), imag (y));

}

inline complex

operator + (const complex& x)

{ 

 return x;

}

inline complex

operator - (const complex& x)

{ 

 return complex (-real (x), -imag (x));

}

inline bool

operator == (const complex& x, const complex& y)

{ 

 return real (x) == real (y) && imag (x) == imag (y);

}

inline bool

operator == (const complex& x, double y)

{

 return real (x) == y && imag (x) == 0;

}

#endif  __MYCOMPLEX__

OX02 关键点

1.防卫式的声明

2.数据写在private里面

3.构造函数的初始化用：

4.const 是否使用分析 如果函数不改变数据加const ，蓝本不变（参数），加const

5.friend ：函数要直接使用别人的数据，同一个类的对象互为friend

6.函数设计，接受是否用reference，传入是否用reference

7.成员函数隐藏的this~ 不能写在参数中，但是函数内可用

8.操作符重构，operator 关键字