为什么for_each这样不能通过编译

[yeyunxiaopan]

#include <afx.h>
#include <iostream.h>
#include <list>
#include <algorithm>

using namespace std;

typedef list<int> int_List;
class A
{

void PrintInt(int n)
{
cout<<n<<endl;

}

void test()
{
int_List nList;

nList.push_back(1);
nList.push_back(2);
nList.push_back(3);
nList.push_back(4);

for_each(nList.begin(),nList.end(),PrintInt);

}

};
void main()
{


}

错误提示
error C2664: 'for_each' : cannot convert parameter 3 from 'void (int)' to 'void (__thiscall *)(int)'

[yeyunxiaopan]

非常感谢，请问楼上的为什么要这样写呢

[珍惜生命远离CPP]

因为PrintInt是成员函数,所以需要将这个函数进行转化成普通的函数.

[yeyunxiaopan]

不好意思，好像还是不行啊

用三楼的方法，错误跟我开始一样

用四楼的方法，错误是 error C2784: 'class std::mem_fun_t<_R,_Ty> __cdecl std::mem_fun(_R (__thiscall _Ty::*)(void))' : could not deduce template argument for '<Unknown>' from 'void (__thiscall A::*)(int)'

[taodm]

楼主什么编译器？不会又是VC6吧？
devcpp下编译通过。

[yeyunxiaopan]

是VC6啊，编译器不支持吗？

[taodm]

VC6就不讨论了。建议你尽早扔了，换VC2005或者devcpp。
用VC6学C++就是浪费生命。

[xfan_hsl]

必须注意一点:for_each()中的函数地址必须是在编译能确定的,所以建议---PrintInt为静态函数

另外,多注意下面的区别:
user-defined generic function
Function as algorithm arguments
Predicate(unary, binary)
Function object

我个人理解是:
1 Suppose you want to add a certain value to all elements of a collection. If you know the value you want to add at compile time, you could use an ordinary function
2 If you need different values that are known at compile time, you could use a
template instead
3 If you need such a function twice, with two different values to add, and both values are processed at runtime, you could use a function objects instead

[mimong_lin]

void PrintInt(list<int>:: iterator p)
{
cout<<*p<<endl;

}

[珍惜生命远离CPP]

这样写
for_each(nList.begin(),nList.end()
,bind1st( mem_fun(&A::PrintInt),this)
);