重载=...马上给分结贴.速度速度..

[WezZai]

#include <iostream>

using namespace std;

class A
{
private:
int s;

public:
A():s(86){};
A& operator+(A& object);
friend std::ostream & operator<< (std::ostream & os, const A& object);
void show(void){cout << s;}
};

std::ostream & operator<< (std::ostream & os, const A& object)
{
os << object.s;
return os;
}


A& A::operator +(A& object)
{
s = object.s + s;
return *this;
}

int main(void)
{
A a,b;
return 0;
}

友员函数operator=不能访问类的private数据成员

[llf_hust]

#include <iostream.h>



class A
{
private:
int s;

public:
A():s(86){};
A& operator+(A& object);
friend ostream & operator<< (ostream & os, const A& object);
void show(void){cout << s;}
};

ostream & operator<< (ostream & os, const A& object)
{
os << object.s;
return os;
}


A& A::operator +(A& object)
{
s = object.s + s;
return *this;
}

int main(void)
{
A a,b;
return 0;
}

[WezZai]

不允许使用这个头文件<iostream.h>
不然我就不会问了

[llf_hust]

这是VC++ 6。0的BUG，必须要这样使用

[WezZai]

呵..那你运行这个..

#include<iostream>
using namespace std;

class Point
{
public:
Point(float a=0,float b=0):x(a),y(b){};
friend ostream &operator<<(ostream&,Point&);
protected:
float x,y;
};
std::ostream &std::operator<<(std::ostream &output,Point &p)
{
output<<"["<<p.x<<","<<p.y<<"]"<<endl;
return output;
}

int main()
{
Point p((float)2.3,(float)3.2);
cout<<p<<endl;
return 0;
}

[WezZai]

搞定了..这样写...

#include <iostream>

using namespace std;

class A
{
private:
int s;

public:
A():s(86){};
A& operator+(A& object);
friend ostream& operator<< (ostream & out,A & object);
void show(void){cout << s;}
};

std::ostream& std::operator<< (std::ostream & out,A & object)
{
out << object.s;
return out;
}


A& A::operator +(A& object)
{
s = object.s + s;
return *this;
}

int main(void)
{
A a,b;
cout << a;
return 0;
}

[xiaocai0001]

解决方案见本版FAQs

http://community.csdn.net/Expert/FAQ/FAQ_Index.asp?id=104766

楼主要学会查找资料.

这个问题在本版已经问过不下10遍了.

[WezZai]

下面继续.

给理由..

满意为止...

[WezZai]

xiaocai0001(萧筱雨)

不好意思..
我很少来...没实在想不通的我都不上坛子.所以就急了点..

[cunsh]

class A;
std::ostream & operator<< (std::ostream & os, const A& object);

把这两行写前面.声明下啊.

[WezZai]

呵..原来是vc6.0的bug...弄了我一晚..
气火..

不用这么麻烦..
只要在定义时operator <<改在std::operator <<就ok啦..