请问这个为什么老是赋值不过去？出错！！！谢谢

[visons]

#include<iostream>
#include<cmath>
using namespace std;
class Point{
protected:
double x,y;
public:
static double PI;
public:
Point(double a=0,double b=0);
double xOffset()const;
double yOffset()const;
double angle()const;
double radius()const;
Point operator+(const Point & d)const;
Point & operator+=(const Point & d);
void moveTo(double a,double b);
void display();


};
Point::Point(double a,double b):x(a),y(b){}
double Point::PI=3.14159265;

double Point::xOffset()const{return x;}
double Point::yOffset()const{return y;}
double Point::angle()const{return (180/PI)*atan2(y,x);}
double Point::radius()const{return sqrt(x*x+y*y);}
void Point::moveTo(double a,double b){x=a,y=b;}
void Point::display(){
cout<<x;}
class Circle :public Point{
double radius;
public:
Circle(const Point&p=Point(),double r=0);
double getRadius()const;
Point getPoint()const;
double getCircum()const;
void moveTo(double a,double b);
void modifyRadius(double r);
};
Circle::Circle(const Point&p,double r):Point(p),radius(r){}
double Circle::getRadius()const{return radius;}
Point Circle::getPoint()const{return static_cast<const Point>(*this);}

double Circle::getCircum()const{return 2*radius*Point::PI;}
void Circle::moveTo(double a,double b){x=a,y=b;}
void Circle::modifyRadius(double r){radius=r;}
int main(){
Point a(2.3,5.6);
Circle c(a,7);
c.moveTo(1,2);
c.modifyRadius(3);
cout<<"the radius is"<<c.getRadius()<<"\n";
cout<<c.getPoint();

cout<<c.getCircum()<<"\n";
}

[visons]

error C2679: binary '<<' : no operator defined which takes a right-hand operand of type 'class Point' (or there is no acceptable conversion)

[jiangheng2008]

Point operator+(const Point & d)const;
Point & operator+=(const Point & d);
函数体在哪？
顺便说一句，BS蛋帖。

[visons]

那个好像不关事的吧！！

[davelv]

貌似<<中间多了个空格...从网上copy的吧..

[davelv]

上面看错了...
错误提示的意思是<<没有定义关于你那个类的操作....

[onion923]

class Point{ 
protected: 
double x,y; 
public: 
static double PI; 
public: 
Point(double a=0,double b=0); 
double xOffset()const; 
double yOffset()const; 
double angle()const; 
double radius()const; 
Point operator+(const Point & d)const; 
Point & operator+=(const Point & d); 
void moveTo(double a,double b); 
void display(); 
friend ostream &operator<<(ostream &os,const Point &p)
{
	os<<p.x<<" "<<p.y<<endl;
	return os;
}

}; 
Point::Point(double a,double b):x(a),y(b){} 
double Point::PI=3.14159265; 

double Point::xOffset()const{return x;} 
double Point::yOffset()const{return y;} 
double Point::angle()const{return (180/PI)*atan2(y,x);} 
double Point::radius()const{return sqrt(x*x+y*y);} 
void Point::moveTo(double a,double b){x=a,y=b;} 
void Point::display(){ 
cout <<x;} 
class Circle :public Point{ 
double radius; 
public: 
Circle(const Point&p=Point(),double r=0); 
double getRadius()const; 
Point getPoint()const; 
double getCircum()const; 
void moveTo(double a,double b); 
void modifyRadius(double r); 
}; 
Circle::Circle(const Point&p,double r):Point(p),radius(r){} 
double Circle::getRadius()const{return radius;} 
Point Circle::getPoint()const{return static_cast <const Point>(*this);} 

double Circle::getCircum()const{return 2*radius*Point::PI;} 
void Circle::moveTo(double a,double b){x=a,y=b;} 
void Circle::modifyRadius(double r){radius=r;} 
void main(){ 
Point a(2.3,5.6); 
Circle c(a,7); 
c.moveTo(1,2); 
c.modifyRadius(3); 
cout <<"the radius is" <<c.getRadius() <<"\n"; 
cout <<c.getPoint(); 

cout <<c.getCircum() <<"\n"; 
}

关注黑体字

[visons]

谢谢~~

[bulltre]

error C2679: binary ' < <' : no operator defined which takes a right-hand operand of type 'class Point' (or there is no acceptable conversion)
错误已经很明显了,不要再发O贴了.