关于<<重载的问题...

[kesaihao862]

#include <iostream>
using namespace std;
class WordCount {
	friend ostream&
		operator<<(ostream&, const WordCount&);
public:
	WordCount( string word, int cnt=1 );
	// ...
private:
	string word;
	int occurs;
};
ostream&
operator <<( ostream& os, const WordCount& wd )
{ // 格式: <occurs> word
	os << "< " << wd.occurs << " > "<< wd.word;
	return os;
}


int main()
{
	WordCount wd( "sadness", 12 );
	cout << "wd:\n" << wd << endl;
	return 0;
}

我这个在VC6下重载<<操作符的程序为什么会通过过呢，明明声明的是友元啊..谁能帮我改下，可以在VC6下运行,等着急用...谢谢

[Supper_Jerry]

做成inline或者放到内部去

[yashiro_]

编译不通过的原因是你的构造函数没有定义！

WordCount( string word, int cnt=1 );

加上定义就行了。

[kesaihao862]

#include <iostream>
#include  <string> 
using namespace std;
class WordCount {
    friend ostream&
        operator<<(ostream&, const WordCount&);
public:
    WordCount( string word, int cnt=1 );
    // ...
private:
    string word;
    int occurs;
};
ostream&
operator <<( ostream& os, const WordCount& wd )
{ // ¸ñʽ: <occurs> word
    os << "< " << wd.occurs << " > "<< wd.word;
    return os;
}
WordCount::WordCount( string word, int cnt=1 )
{}

int main()
{
    WordCount wd( "sadness", 12 );
    cout << "wd:\n" << wd << endl;
    return 0;
}

根据楼上几位的建议，我改了一下，可是还是通不过．．

还有，不要以说ＶＣ６差劲是垃圾来显示自己的水平．．．有本事你自己做个啊．．．

[OenAuth.Net]

#include <iostream>
#include <string>
using namespace std;
class WordCount {
friend ostream& operator<<(ostream&, const WordCount&);
public:
WordCount(string wordTemp,int cnt);
private:
string word;
int occurs;
};
ostream& operator <<( ostream& os, const WordCount& wd )
{ // 格式: <occurs> word
os << "< " << wd.occurs << " > "<< wd.word;
return os;
}
WordCount::WordCount(string wordTemp,int cnt){
word=wordTemp;
occurs=cnt;
}
int main()
{
WordCount wd( "sadness", 12 );
cout << "wd:\n" << wd << endl;
return 0;
}


你错在下面几个方面：
一、没有实现构造函数；
二、构造函数中不能使用默认参数；WordCount( string word, int cnt=1 )不能将cnt=1;
三、构造函数中的参数不能使用类成员变量，WordCount( string word, int cnt=1 )不能用word

[OenAuth.Net]

更正一下我上面的解释：
#include <iostream>
#include <string>
using namespace std;
class WordCount {
friend ostream& operator<<(ostream&, const WordCount&);
public:
WordCount(string wordTemp,int cnt=1);//但可以用word，但最好别用。这里可以初始化cntprivate:
string word;
int occurs;
};
ostream& operator <<( ostream& os, const WordCount& wd )
{ // 格式: <occurs> word
os << "< " << wd.occurs << " > "<< wd.word;
return os;
}

//实现构造函数
WordCount::WordCount(string wordTemp,int cnt){//注意：不能将cnt=1
word=wordTemp;
occurs=cnt;
}
int main()
{
WordCount wd( "sadness", 12 );
cout << "wd:\n" << wd << endl;
return 0;
}

[jieao111]

还有，不要以说ＶＣ６差劲是垃圾来显示自己的水平．．．有本事你自己做个啊．．．

还有啥说的，

[hastings]

试试:

#include <iostream>
#include  <string> 
using namespace std;
class WordCount ;
ostream&
operator <<( ostream& os, const WordCount& wd );
class WordCount {
    friend ostream&
        operator<<(ostream&, const WordCount&);
public:
    WordCount( string word, int cnt=1 );
    // ...
private:
    string word;
    int occurs;
};
ostream&
operator <<( ostream& os, const WordCount& wd )
{ // ¸ñʽ: <occurs> word
    os << "< " << wd.occurs << " > "<< wd.word;
    return os;
}
WordCount::WordCount( string word, int cnt=1 )
{}

int main()
{
    WordCount wd( "sadness", 12 );
    cout << "wd:\n" << wd << endl;
    return 0;
}

[wuyn_1984]

7楼是亮点

[就呆在云上]

你的构造函数有问题
这个东西不是vc6的问题吧，不过我挺讨厌vc6的
修改如下：

#include <iostream>
#include  <string> 
using namespace std;
class WordCount {
    friend ostream&
        operator<<(ostream&, const WordCount&);
public:
	
    WordCount( string worddd , int cnt=1 );
    // ...
private:
    string word;
    int occurs;
};


ostream&
operator <<( ostream& os, const WordCount& wd )
{ // ¸ñʽ: <occurs> word
    os << "< " << wd.occurs << " > "<< wd.word;
    return os;
}
WordCount::WordCount( string worddd, int cnt)
{
	word = worddd;
	occurs = cnt;
}

int main()
{
    WordCount wd( "sadness", 12 );
    cout << "wd:\n" << wd << endl;
    return 0;
}

[Vitin]

构造函数的问题不谈。单就友元而言，我知道VC6开放std名字空间后operator<<友元会有问题的。

可以去掉 using namespace std; 试试，如
#include <iostream>
#include <string>
using std::ostream;
using std::string;
using std::cout;
using std::endl;
...

[cx36001390]

1.vc6环境下这句话不要忘记加.
#include "stdafx.h"

2.构造函数的参数不要和成员变量同名.

[IT_lau]

up

[wuyecandi]

没定义构造函数,

[baihacker]

VC6的有问题..
#include <string>
并实现WordCount的constructor后DEVC++通过

[星羽]

#include <iostream>
#include <string>
using namespace std;

class WordCount {
    friend ostream& operator<<(ostream&, const WordCount&);
public:
    WordCount( string word, int cnt=1 );
private:
    string word;
    int occurs;
};

WordCount::WordCount(string word, int cnt/* =1  */)
{
    this->word = word;
    occurs = cnt;
}

ostream& operator <<( ostream& os, const WordCount& wd )
{ 
    os << "< " << wd.occurs << " > "<< wd.word;
    return os;
}


int main()
{
    WordCount wd( "sadness", 12 );
    cout << "wd:\n" << wd << endl;
    return 0;
}

[ryfdizuo]

只是一个警告吧，有可能会堆栈溢出...

[ttkk_2007]

扔了vc6

[taodm]

class WordCount {
friend ostream&
operator<<(ostream&, const WordCount&)
{ // 格式: <occurs> word
os << "< " << wd.occurs << " > "<< wd.word;
return os;
}


public:
WordCount( string word, int cnt=1 );
// ...
private:
string word;
int occurs;
};