我提两个解决方案吧：
方案一：在类中加入自己的判断函数，然后绑定：
#include <iostream>
#include <vector>
#include <string>
#include <functional>
using namespace std;
typedef string tstring; //FOR TEST
struct struTriad
{
tstring u;
tstring v;
int iNum;
bool equalU(const struTriad n) const {return n.u == u;}
};
int main()
{
vector <struTriad> m_vtrUU;
struTriad u;
vector <struTriad>::iterator it =
find_if(m_vtrUU.begin(),m_vtrUU.end(),
bind2nd(mem_fun_ref(&struTriad::equalU), u));
}
方案2：也就是LZ的方案，不过用binary_function更清楚，也避免了效率问题：
#include <iostream>
#include <vector>
#include <string>
#include <functional>
using namespace std;
typedef string tstring; //FOR TEST
struct struTriad
{
tstring u;
tstring v;
int iNum;
};
class strInStruVtr:public std::binary_function <struTriad, struTriad, bool>
{
public:
bool operator()(const struTriad& a, const struTriad& b) const {
return a.u==b.u;
}
};
int main()
{
vector <struTriad> m_vtrUU;
struTriad u;
vector <struTriad>::iterator it =
find_if(m_vtrUU.begin(),m_vtrUU.end(),
bind2nd(strInStruVtr(), u));
}
对了，楼主应该是在MFC里面搞的吧？
typedef string tstring; //FOR TEST
这一句是为了避免麻烦，LZ自行删除就行了
