的线程构造函数会将它的参数，而的消息类型是不可拷贝。传递给需要使用的目标函数的引用的boost :: REF（MSG）

The thread constructor copies its arguments, and the message type is not copyable. To pass a reference to the target function you need to use boost::ref(msg)

另外请注意，使用绑定与线程是多余的：

Also note that using bind with thread is unnecessary:

boost::thread thrd(&handover_request_handler, boost::ref(msg), boost::ref(ec));

的线程构造实现了相同的语义绑定，因此，使用绑定只是增加了不必要的额外拷贝。

The thread constructor implements the same semantics as bind, so using bind just adds unnecessary additional copying.