find_if和函数对象结合实现对自定义类型vector的查找

实现NAT穿透需要对client的IP和port 进行同时查找，这就需要自定义的结构体，然后声明一个此种类型的vector,每次客户发起连接的时候都要查找一下此表，如果存在此客户端的ip 和port 就返回，否则将此结构体加入到转发列表中。
#include "stdafx.h"

#include <iostream>

#include <string>
#include <functional>
#include <list>
#include <vector>
#include <algorithm>
using namespace std;

typedef struct __NAT
{
char userip[30];
int userport;
} natType;
//查找类

class FindIP
{
public:
bool operator()(natType& dValue)
{
return (strcmp(dValue.userip,m_val.userip)==0)&&dValue.userport==m_val.userport;

}

static void SetUserNat(natType dval)
{
m_val = dval;
}
private:
static natType m_val;
};

natType natvalue,destvalue;
natType FindIP::m_val = natvalue;
int main(int argc, char* argv[])
{ vector <natType> userList;
natType tempnat;
strcpy(tempnat.userip,"192.168.0.1");
tempnat.userport=9000;
userList.push_back(tempnat);
//,destvalue;
strcpy(natvalue.userip,"192.168.0.1");
natvalue.userport=9000;
FindIP::SetUserNat(natvalue);

vector <natType> :: iterator iter=find_if(userList.begin(), userList.end(), FindIP()) ;
if(iter==userList.end())
{
/* strcpy(destvalue.userip,(*iter).userip);
*/destvalue.userport=(*iter).userport;
printf("nothing/n");

userList.push_back(natvalue);
}

return 0;
}