#include<iostream>
#include"student.h"
using namespace std;
CStudent::CStudent()
{
    strName="General Student";
    chinese=0;
    math=0;
    english=0;
}

CStudent::CStudent(std::string Name,double c,double m,double e)
{
    strName=Name;
    chinese=c;
    math=m;
    english=e;
}

CStudent CStudent::operator +(CStudent S)
{ 
    CStudent temp;
    temp.strName="Total Performance";
    temp.chinese=this->chinese+S.chinese;
    temp.math=this->math+S.english;
    temp.english=this->english+S.english;
    return temp;
}

ostream& operator <<(ostream& out,CStudent& S)
{
    out<<S.strName<<"("<<S.chinese<<" , "<<S.math<<" , "<<S.english<<")"<<endl;
    return out;
}

void CStudent::SetChinese(double a)
{
    chinese=a;
}

void CStudent::SetMath(double a)
{
    math=a;
}

void CStudent::SetEnglish(double a)
{
    english=a;
}

double CStudent::returnChinese()
{
    return chinese;
}

double CStudent::returnMath()
{
    return math;
}

double CStudent::returnEnglish()
{
    return english;
}

double CStudent::returnTotalPerformance()
{
    return chinese+math+english;
}

double CStudent::returnAverage()
{
    return (chinese+math+english)/3;
}

string CStudent::returnName()
{
    return strName;
}

这里是类的实现 大家看下

#include <iostream>
#include <string>

using namespace std;

class CStudent
{
    public:
        CStudent();
        CStudent(std::string Name,double c,double m,double e);
        CStudent operator +(CStudent S);
        friend ostream& operator <<(ostream& out,CStudent& S);
        void SetChinese(double a);
        void SetMath(double a);
        void SetEnglish(double a);
        double returnChinese();
        double returnMath();
        double returnEnglish();
        double returnTotalPerformance();
        double returnAverage();
        string returnName();
    private:
        string strName;
        double chinese;
        double math;
        double english;
};

CStudent::CStudent()
{
    strName="General Student";
    chinese=0;
    math=0;
    english=0;
}

CStudent::CStudent(std::string Name,double c,double m,double e)
{
    strName=Name;
    chinese=c;
    math=m;
    english=e;
}

CStudent CStudent::operator +(CStudent S)
{
    CStudent temp;
    temp.strName="Total Performance";
    temp.chinese=this->chinese+S.chinese;
    temp.math=this->math+S.english;
    temp.english=this->english+S.english;
    return temp;
}

ostream& operator <<(ostream& out,CStudent& S)
{
    out<<S.strName<<"("<<S.chinese<<" , "<<S.math<<" , "<<S.english<<")"<<endl;
    return out;
}

void CStudent::SetChinese(double a)
{
    chinese=a;
}

void CStudent::SetMath(double a)
{
    math=a;
}

void CStudent::SetEnglish(double a)
{
    english=a;
}

double CStudent::returnChinese()
{
    return chinese;
}

double CStudent::returnMath()
{
    return math;
}

double CStudent::returnEnglish()
{
    return english;
}

double CStudent::returnTotalPerformance()
{
    return chinese+math+english;
}

double CStudent::returnAverage()
{
    return (chinese+math+english)/3;
}

string CStudent::returnName()
{
    return strName;
}



int main()
{
    CStudent s1("yeah", 1.00, 100.00, 100.00);
    cout << s1 << endl;
    cout << "Hello world!" << endl;

    return 0;
}

输出：
yeah(1 , 100 , 100)

Hello world!

Process returned 0 (0x0)   execution time : 0.000 s
Press any key to continue.

正确啊，没有发现有什么问题啊。

VC6下面试了下，也行啊。。没有问题啊。

那我 衰了 咋回事？

为什么出现这个？

friend ostream& operator <<(ostream& out,CStudent& S);
你没有指定友元重载<< 或是 >> ？看C++ primer上的解释吧。