function.cpp

#include <iostream>
#include <functional>

using namespace std;

void f(std::function<void(int)> call) {
    call(1);
    call(2);
    call(3);
}

int main()
{
    int x = 42;
    f([&](int param) {
        x += param;
        cout << "param is " << param << ", x is " << x << endl;
    });

    return 0;
}