c++ STL仿函数的一个学习问题

Question

count累加器，看看加法仿函数一共调用了多少次。

//请问为什么count的输出是0
#include<iostream>
using namespace std;

class MyAdd
{
public:

    int operator()(int a, int b)
    {
        return a + b;
        count++;
    }

private:
    static int count;


    friend void showCount();
};

int MyAdd::count = 0;

void showCount()
{
    cout << MyAdd::count << endl;
}

class MyPrint
{
public:
    void operator()(string text)const
    {
        cout << text << endl;
    }
};

void doPrint(const MyPrint& m, string text)
{
    m(text);
}

int main()
{
    MyAdd m;
    cout << m(30, m(10, 20)) << endl;
    showCount();
    MyPrint m2;
    doPrint(m2,"Hello World");

}

Answer 1

    int operator()(int a, int b)
    {
        count++;
        return a + b;

    }

要写在 return 前面啊