Debounce in C++

Question

I'm trying to write a dummy debounce function in c++. Here is what I have written:

 #include <bits/stdc++.h>
    using namespace std;
    using namespace chrono;
    function<void(int)>debounce(function<void(void)>&f , int period){
        function<void(int)> fn = [&](int per){
            static auto init_time = high_resolution_clock::now();
            auto final_time = high_resolution_clock::now();
            if ( duration_cast<milliseconds>(final_time - init_time).count() > per){
                f();
            }
            init_time = final_time;
        };
        return fn;
    }
    int main(void){
        int x = 0;
        function<void(void) > f = [&x](void){
            x++;
        };
        function<void(int)> xdf = debounce(f , 30);
        std::this_thread::sleep_for(milliseconds(300));
        xdf(300);
        xdf(300);
        std::this_thread::sleep_for(milliseconds(300));
        xdf(300);
        if(x>=3 || x != 2){
            cout << "Debounce failed" << '\n'; 
        }else {
            cout << "Successful" << '\n'; 
        }
        return 0;
    }

But this doesn't work fine. Is there any way so that I don't have to pass the time limit to xdf function? Maybe this is not the correct code. Can you give some other ideas to implement or correct this one?

Answer 1

A convertion word to word of the go implementation you linked.

#include <bits/stdc++.h>
#include <stdexcept>
using namespace std;
using namespace chrono;

function<void()> Debounced(function<void()>&f , int period){
    static auto created = high_resolution_clock::now();
    // "=" allow to pass by copy all used variables (created and period)
    // "&f" allow to pass by reference f variable
    function<void()> fn = [=,&f](){
        auto now = high_resolution_clock::now();
        if (duration_cast<milliseconds>(now - created).count() > period){
            f();
        }
    };
    return fn;
}

int main(void){
    int x = 0;
    function<void()> f = [&x](){
        x++;
    };

    auto dbf = Debounced(f, 500);
    for (int i = 0; i < 10; ++i) {
      dbf();
    }
    if (x != 0) {
      throw std::runtime_error("Expected x not to change since it's debounced for 500ms");
    }
    std::this_thread::sleep_for(milliseconds(500));
    for (int i = 0; i < 10; ++i) {
      dbf();
    }
    if (x != 10) {
      throw std::runtime_error("Expected x to be incremented 10 times");
    }
}