仅复制类对象的某些部分/字段

I have a class like so:

我有一个这样的课:

class ThreadPool
{
   thread *th;
   void evFn(void);
   unsigned i;
   queue<function<void()>> Queue;
   //mutex Queue_Mutex;
   //condition_variable Cond_Var;
}
class Thr