程序代码：

#include <iostream>
using namespace std;

#include <map>
#include <string>

template <typename T>
class MyGreater
{
public:
    bool operator()(T& left,T& right)
    {
        return left > right;
    }
};

int main(int argc, char *argv[])
{
    map<int, string, MyGreater<int> > maptest;
    maptest.insert(pair<int,string>(1,"aaa"));
    return 0;
}