C++ C2679结构上下文

Hi stack overflow我对stl中的集合有问题，我的问题是：

输入：

3
2,2,3
American Beauty#2002
Iron Man#2012
Interstellar#2014
Iron Man#2012
Inception#2010
Forrest Gump#1994
Iron Man#2012

SetTask2.h：

#pragma once
#include <set>
#include <vector>
#include <iostream>
#include <string>
#include <fstream>
#include <iterator>
#include <algorithm>

using namespace std;

struct Movie {
    string movieName;
    int movieYear;
};

bool operator<(const Movie& m1, Movie& m2);
void SetTask2();

然后我得到这个错误：

错误C2679二进制'

---

错误C2679 binary“您能发布足够的代码让我们重现此问题吗？我怀疑错误可能是定义

运算符我现在用文件内容编辑问题。谢谢你现在一切都清楚了！！祝您愉快：D，我忘记了第二个参数的常数。。。
    #include "SetTask2.h"

bool operator<(const Movie& m1, Movie& m2) {
    return m1.movieYear <= m2.movieYear;
}

void SetTask2() {
    ifstream in("SetTask2.in");
    int numberOfPersons;
    in >> numberOfPersons;

    vector<set<Movie>> preferences;

    string prefNumberS;
    in >> prefNumberS;
    for (int i = 0; i < prefNumberS.size(); i++) {
        if (prefNumberS[i] != ',') {
            int number = (int)prefNumberS[i] - 48;

            string mName;
            string mYear;

            Movie m;
            set<Movie> s;

            for (int j = 0; j < number; j++)
            {
                getline(in, mName, '#');
                getline(in, mYear, '\n');
                m.movieName = mName;
                m.movieYear = stoi(mYear);

                s.insert(m);
                preferences.push_back(s);
            }
        }
    }
}

#include "SetTask2.h"

using namespace std;

int main()
{

    SetTask2(); // Set : Task 2

    return 0;
}

bool operator < (const Movie& left, const Movie& right) {

    return left.movieYear < right.movieYear;
}