list的排序问题. (续)
#include <list >
using namespace std;

struct student
{
int id;
char name[20];
};

bool compfn(student x,student y)
{
if(x.id > y.id)
return true;
else
return false;
}

void main()
{
list <student > l;
student st;

st.id = 1;
strcpy(st.name,"aaa");
l.push_back(st);
st.id = 3;
strcpy(st.name,"bbb");
l.push_back(st);
st.id = 2;
strcpy(st.name,"ccc");
l.push_back(st);

l.sort(compfn);
}

编译不过:
error C2664: 'void __thiscall std::list <struct student,class std::allocator <struct student > >::sort(struct std::greater <struct student >) ' : cannot convert parameter 1 from 'bool (struct student,struct student) ' to 'struct
std::greater <struct student > '

怎样修改?

有人说是VC6的BUG,建议如下修改:
struct compfn
{
bool operator ()(student &x,student &y)
{
if(x.id > y.id)
return true;
else
return false;
}
};

然后调用sort的语句改为l.sort(compfn());
但还是编译不过:

error C2664: 'void __thiscall std::list<struct student,class std::allocator<struct student> >::sort(struct std::greater<struct student>)' : cannot convert parameter 1 from 'struct compfn' to 'struct std::greater<s
truct student>'
No constructor could take the source type, or constructor overload resolution was ambiguous

http://topic.csdn.net/u/20071016/23/ef0602c3-c926-4780-ba7e-d67c94618347.html


[解决办法]
刚才的方法在g++下面没问题，
VC6下面你用下面的方法，不用定义compfn
bool operator > (student const& x, student const& y)
{
if(x.id > y.id)
return true;
else
return false;
}
l.sort(std::greater<student>());
这样改应该没问题了吧