STL c++11 function object 有关判断式

Question

代码是写一个function object

#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;

class myPredicate
{
private:
    int initNum;
    int count;
public:
    myPredicate(int i)
    {
        count = i;
        initNum = 0;
    }

    bool operator()(int ) //一定要加int或者int i，为何？？？   之前写过返回值是int的function object不需要加
    {
        return ++initNum == count;
    }
};

int main()
{
    vector<int>myVector = {1,2,3,4,5,6,7,8,9};

    for (int i : myVector) cout << i << " ";

    remove_if(myVector.begin(), myVector.end(), myPredicate(3));//调用后不会复原，可能VS2010上会复原，我用的是2017

    cout << endl;

    for (int i : myVector) cout << i << " ";

    system("pause");
}

Answer 1

https://blog.csdn.net/weixin_34390105/article/details/86054544