[New] Thread inside class

#include <iostream>
#include <thread>
#include <chrono>
#include <ctime>
#include <set>


class tmp {
private:
    std::set<std::thread::id> ativo;
    int n;

public:
    void print_n() {
        std::this_thread::sleep_for(std::chrono::seconds(1));

        if(ativo.find(std::this_thread::get_id()) != ativo.end()) {

            std::cout << n << std::endl;
            this->tmp::print_n();
        }
    }

    void stop(std::thread::id t) {
        ativo.erase(t);
        return;
    }
    void set(int v) {
        n = v;
        return;
    }

    std::thread::id print() {
        std::thread prt_thread(&tmp::print_n, this);

        ativo.insert(prt_thread.get_id());

        prt_thread.detach();
        return prt_thread.get_id();
    }
};


int main()
{
    tmp TMP;
    TMP.set(5);

    std::thread::id the_thread = TMP.print();

    while(true) {
        int get;
        std::cin >> get;
        if(get == 0) {
            TMP.stop(the_thread);
            break;
        }
        TMP.set(get);
    }

    return 0;
}