一个C++的小问题,真烦人啊!!一个<<重载的问题

Question

以下是代码:
#include<iostream>
using namespace std;

class point{
double x;
double y;
public:
point();
point(double tx,double ty);
point(point &p){
cout<<"copy function."<<endl;
x=p.x;
y=p.y;
}
double getx();
double gety();
void print();
friend ostream & operator<<(ostream &stream, point &p);
};
ostream & operator << (ostream &stream,point &p)
{
stream<<"[Point ("<<p.x<<","<<p.y<<")]"<<endl;
return stream;
}
void point::print(){
cout<<"[Point ("<<x<<","<<y<<")]"<<endl;
}
double point::gety()
{
return y;
}
double point::getx()
{
return x;
}
point::point(){
x=0.0;
y=0.0;
cout<<"default constructor."<<endl;
}
point::point(double tx,double ty){
x=tx;
this->y=ty;
cout<<"normal constrator."<<endl;
}
void main(){
point p1(1,1),p2;
cout<<p1<<p2;
}
狂出现:error C2248: 'x' : cannot access private member declared in class 'point'!
完整的输出是:
--------------------Configuration: test3 - Win32 Debug--------------------
Compiling...
Text1.cpp
e:\c++\c++projects\learning\test3\text1.cpp(22) : error C2248: 'x' : cannot access private member declared in class 'point'
e:\c++\c++projects\learning\test3\text1.cpp(5) : see declaration of 'x'
e:\c++\c++projects\learning\test3\text1.cpp(22) : error C2248: 'y' : cannot access private member declared in class 'point'
e:\c++\c++projects\learning\test3\text1.cpp(6) : see declaration of 'y'
e:\c++\c++projects\learning\test3\text1.cpp(48) : error C2593: 'operator <<' is ambiguous
执行 cl.exe 时出错.

test3.exe - 1 error(s), 0 warning(s)

Answer 1

public:
double x;
double y;