simple threading c++ with callable object

thread_with_callable.cpp

#include <iostream>
#include <thread>

class F {
 private:
  int data;

 public:
  F(int data_) : data(data_) {}
  F(const F &other) : data(other.data) { std::cout << "copy!" << std::endl; }
  F(F &&other) : data(std::move(other.data)) {
    std::cout << "move!" << std::endl;
  }
  F &operator=(const F &other) {
    std::cout << "copy assign!" << std::endl;
    data = other.data;
    return *this;
  }
  F &operator=(F &&other) {
    std::cout << "move assign!" << std::endl;
    data = std::move(other.data);
    return *this;
  }
  void operator()() {
    std::cout << std::this_thread::get_id() << ": " << data << std::endl;
  }
};

int main(int argc, char const *argv[]) {
  F f(3);
  std::thread t1{f};
  // print:
  //   copy!
  //   move!
  t1.join();
  std::thread t2{F(4)};
  // print:
  //   move!
  //   move!
  t2.join();
  return 0;
}