您通过值将参数传递给func，这应该构成第二步.显然，std::thread在调用func之前在内部又存储了一次，根据标准，AFAIK是绝对合法的.

You pass argument to func by value which should constitute the second move. Apparently std::thread stores it internally one more time before calling func, which AFAIK is absolutely legal in terms of the Standard.