求助 声明友元函数 依然无法访问private数据

[qq_30499345]

Coordinate.h

#ifndef COORDINATE_H
#define COORDINATE_H
class Coordinate
{
	friend ostream & operator<<(ostream& out, Coordinate & coor);
	friend Coordinate operator+(const Coordinate &c1, const Coordinate &c2);
private:
	int m_iX;
	int m_iY;
public:
	Coordinate(int x, int y);
	int getX();
	int getY();
	
	/*Coordinate operator+(const Coordinate &c);*/
};
#endif

Coordinate.cpp

#include "Coordiante.h"
#include<iostream>
#include<ostream>
using namespace std;


Coordinate::Coordinate(int x, int y)
{
	m_iX = x;
	m_iY = y;
}

int Coordinate::getX()
{
	return m_iX;
}

int Coordinate::getY()
{
	return m_iY;
}

//Coordinate Coordinate::operator+(const Coordinate & c)
//{
//	Coordinate temp(0,0);
//	temp.m_iX = this->m_iX + c.m_iX;
//	temp.m_iY = this->m_iY + c.m_iY;
//	return temp;
//}

ostream & operator<<(ostream & out, Coordinate & coor)
{
	out << coor.m_iX << ":" << coor.m_iY ;
	return out;
}

Coordinate operator+(const Coordinate & c1, const Coordinate & c2)
{
	Coordinate temp(0,0);
	temp.m_iX = c1.m_iX + c2.m_iX;
	temp.m_iY = c1.m_iY + c2.m_iY;
	return temp;
}
	

demo.cpp

#include"Coordiante.h"
#include<iostream>
using namespace std;

int main()
{
	Coordinate c1(1, 3);
	Coordinate c2(2, 3);
	Coordinate c3(0, 0);
	c3 = c1 + c2;
	cout << c3<<endl;
	system("pause");
}

IDE环境是VS2016 问题在于定义输出符号的重载的时候，VS提示无法访问m_iX 和m_iY