STL 에서 find_if 사용시 변수를 하나 더 쓰고싶을때는 어떻게 하나요?

#include <iostream>
#include <algorithm>
#include <map>
#include <functional>
#include <boost/bind.hpp>
 
namespace std {
    namespace tr1 = boost;
}
 
 
typedef std::multimap<double, int> DataType;
 
 
struct DataFind : public std::unary_function<DataType::value_type, bool>
{
    bool operator()(const DataType::value_type &value) const 
    {
        return (value.first == FindValue);
    }
 
    double FindValue;
};
 
 
bool DataFindFunc(const DataType::value_type value, const double FindValue)  
{
    return (value.first == FindValue);
}
 
 
void Init(DataType &data)
{
    data.insert(DataType::value_type(10.0, 1));
    data.insert(DataType::value_type(20.0, 2));
    data.insert(DataType::value_type(30.0, 3));
    data.insert(DataType::value_type(40.0, 4));
    data.insert(DataType::value_type(50.0, 5));
}
 
int main()
{
    using namespace std;
 
    DataType data;
    Init(data);
 
 
    { // 함수객체 방식 
        DataFind Finder;
        Finder.FindValue = 30;
 
        DataType::iterator it = std::find_if(data.begin(), data.end(), Finder);
 
        if (it != data.end()) {
            cout << it->first << " : " << it->second << endl;
        }
        else {
            cout << "not found " << endl;
        }
    }
 
    {  // 바인더 이용하기 
        double FindValue = 20;
 
        DataType::iterator it = std::find_if(data.begin(), data.end(), std::bind2nd(std::ptr_fun(DataFindFunc), FindValue));
 
        if (it != data.end()) {
            cout << it->first << " : " << it->second << endl;
        }
        else {
            cout << "not found " << endl;
        }
    }
 
    {  // 새로운 바인더 이용하기 
        double FindValue = 20;
 
        DataType::iterator it = std::find_if(data.begin(), data.end(), std::tr1::bind(DataFindFunc, _1, FindValue));
 
        if (it != data.end()) {
            cout << it->first << " : " << it->second << endl;
        }
        else {
            cout << "not found " << endl;
        }
    }
 
 
}