一点关于c++输入输出与重载的问题

Question

#include
#include
#include
using namespace std;
struct student
{
int no;
string name;
};
class studentarray
{
private:
student* p;
ifstream infile;
int count = 0;
student st;
int max_num = 3;
public:
studentarray(){}
friend istream& operator >>(istream& in, student& st);
friend ostream& operator <<(ostream& out, student& st);
studentarray(ifstream& in)
{
p = new student[max_num];
in >> st;
while (!in.eof())
{
p[count] = st;
count++;
in >> st;
if (count == max_num)
{
max_num = 2;
student q = new student[max_num];
for (int i = 0; i < count; i++) q[i] = p[i];
delete[]p;
p = q;
}
}
}
~studentarray()
{
ofstream outfile("d:\student.bat");
int i = 0;
while (i < count)
{
i++;
outfile << p[i];
}
outfile.close();
}

};
istream& operator >>(ifstream& in, student& st)
{
in >> st.no >> st.name;
return in;
}
ostream& operator <<(ostream& out, student& st)
{
out << st.no << " " << st.name << endl;
return out;
}
int main()
{
student st;
ifstream infile("d:\student.bat");
if (infile.fail())
{
cout << "请输入学生的学号与姓名，并用EOF结束输入" << endl;
ofstream outfile("d:\student.bat");
while ((cin >> st) != EOF)
{
outfile << st;
cin >> st;
}
cout << "您的数据已成功写入d:\student.dat，请重新打开本程序" << endl;
outfile.close();
infile.close();
}
else
{
studentarray array1(infile);
cout << "已成功读取数据文件！" << endl;
}
}

代码如上
编译器提示： 二进制">>"没有找到接受“student”类型的右操作数的运算符(或没有可接受的转换)
二进制“<<”: 没有找到接受“student”类型的右操作数的运算符(或没有可接受的转换)

诸如此类的提示有七八个，请问我的代码哪里有问题？

Answer 1

//问题有点多，看看。 fstream istream不能通用。 cin是istream.

#include <iostream>
#include <fstream>
using namespace std;
struct student
{
    int no;
    string name;
};
istream &operator>>(istream &in, student &st)
{
    in >> st.no >> st.name;
    return in;
}
ostream &operator<<(ostream &out, student &st)
{
    out << st.no << " " << st.name << endl;
    return out;
}

class studentarray
{
private:
    student *p;
    ifstream infile;
    int count = 0;
    student st;
    int max_num = 3;

public:
    studentarray() {}
    friend istream &operator>>(istream &in, student &st);
    friend ostream &operator<<(ostream &out, student &st);
    studentarray(ifstream &in)
    {
        p = new student[max_num];
        in >> st;
        while (!in.eof())
        {
            p[count] = st;
            count++;
            in >> st;
            if (count == max_num)
            {
                max_num = 2;
                student *q = new student[max_num];
                for (int i = 0; i < count; i++)
                    q[i] = p[i];
                delete[] p;
                p = q;
            }
        }
    }
    ~studentarray()
    {
        ofstream outfile("d:\\student.bat");
        int i = 0;
        while (i < count)
        {
            i++;
            outfile << p[i];
        }
        outfile.close();
    }
};

int main()
{
    student st;
    ifstream infile("d:\\student.bat");
    if (infile.fail())
    {
        cout << "请输入学生的学号与姓名，并用EOF结束输入" << endl;
        ofstream outfile("d:\\student.bat");
        while ((cin >> st))
        {
            outfile << st;
            cin >> st;
        }
        cout << "您的数据已成功写入d:\\student.dat，请重新打开本程序" << endl;
        outfile.close();
        infile.close();
    }
    else
    {
        studentarray array1(infile);
        cout << "已成功读取数据文件！" << endl;
    }
}