raii确保c++11线程被join

scoped_thread.cpp

class scoped_thread
{
  std::thread t;
public:
  explicit scoped_thread(std::thread t_) : t(std::move(t_)) {
    if (!t.joinable()) {
      throw std::logic_error(“No thread”);
    }
  }
  ~scoped_thread() {
    t.join();
  }
  scoped_thread(scoped_thread const &) = delete;
  scoped_thread &operator=(scoped_thread const &) = delete;
};