    inline unsigned int wait(const unsigned int milliseconds) {
      cimg::mutex(3);
      static cimg_uint64 timer = cimg::time();
      cimg::mutex(3,0);
      return cimg::wait(milliseconds,&timer);
    }
    inline unsigned int wait(const unsigned int milliseconds) {
      cimg::mutex(3);
      static cimg_uint64 timer = cimg::time();
      cimg::mutex(3,0);
      return cimg::wait(milliseconds,&timer);
    }