what's wrong? error C2664

[latofi]

student.h

#ifndef STUDENT_H_
#define STUDENT_H_

#include <iostream>
#include <string>
#include <valarray>

class Student
{
private:
	typedef std::valarray<double> ArrayDb;
	std::string name;
	ArrayDb scores;
	std::ostream & arr_out(std::ostream & os) const;
public:
	Student(): name("Null Student"), scores() { }
	Student(const std::string & s): name(s), scores() { }
	explicit Student(int n): name("Nully"), scores(n) { }
	Student(const std::string & s, int n): name(s), scores(n) { }
	Student(const std::string & s, const ArrayDb & a): name(s), scores(a) { }
	Student(const char *str, const double *pd, int n): name(str), scores(pd, n) { }
	~Student() { }
	double Average() const;
	const std::string & Name() const;
	double & operator[] (int i);
	double operator[] (int i) const;
	friend std::istream & operator>> (std::istream & is, Student & stu);
	friend std::istream & getline(std::istream & is, Student & stu);
	friend std::ostream & operator<< (std::ostream & os, const Student & stu);
};
#endif

student.cpp

#include "student.h"
using std::ostream;
using std::endl;
using std::istream;
using std::string;

double Student::Average() const
{
	if(scores.size() > 0)
		return scores.sum() / scores.size();
	else
		return 0;
}

const string & Student::Name() const
{
	return name;
}

double & Student::operator[] (int i)
{
	return scores[i];
}

double Student::operator[] (int i) const
{
	return scores[i];
}

ostream & Student::arr_out(ostream & os) const
{
	int i;
	int lim = scores.size();
	if(lim > 0)
	{
		for(i = 0; i < lim; i++)
		{
			os << scores[i] << " ";
			if(i % 5 == 4)
				os << endl;
		}
		if(i % 5 != 0)
			os << endl;
	}
	else
		os << " empty array ";
	return os;
}

istream & operator>> (istream & is, Student & stu)
{
	is >> stu.name;
	return is;
}

istream & getline(istream & is, Student & stu)
{
	getline(is, stu.name);
	return is;
}

ostream & operator<< (ostream & os, const Student & stu)
{
	os << "Scores for " << stu.name << ":\n";
	stu.arr_out(os);
	return os;
}

--------------------Configuration: student - Win32 Debug--------------------
Compiling...
student.cpp
C:\Documents and Settings\lin\桌面\student.cpp(58) : error C2664: 'getline' : cannot convert parameter 2 from 'class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >' to 'class Student &'
A reference that is not to 'const' cannot be bound to a non-lvalue
Error executing cl.exe.

student.obj - 1 error(s), 0 warning(s)

[mstlq]

istream & getline(istream & is, Student & stu)
{
    getline(is, stu.name);
    return is;
}

改成

istream & getline(istream & is, Student & stu)
{
    std::getline(is, stu.name);
    return is;
}

[cocat]

哇~好快~

using std::ostream;
using std::endl;
using std::istream;

改成

using namespace std;

[traceless]

Faint~~~

lz能写出这样的代码，这个错误居然不会改。。。

[latofi]

不是我写的，是抄着primer plus上面的类，然后再自己写的定义。自己再对照书上。但是书上也是这样的啊。。

[最帅马老师]

[Quote=引用 4 楼 latofi 的回复:]
不是我写的，是抄着primer plus上面的类，然后再自己写的定义。自己再对照书上。但是书上也是这样的啊。。
[/Quote]

书上有几处在VS中编译不过去的。记得有一处讲内存分配时的free链表节点时就有问题

[cocat]

[Quote=引用 5 楼 kktemp234 的回复:]
引用 4 楼 latofi 的回复:
不是我写的，是抄着primer plus上面的类，然后再自己写的定义。自己再对照书上。但是书上也是这样的啊。。


书上有几处在VS中编译不过去的。记得有一处讲内存分配时的free链表节点时就有问题
[/Quote]

书中的不可能都是可运行的程序，这个事很正常的，可能它用的编译器不一样也是可能得