C + + does not automatically generate related functions such as assignment, copy function

By default, if some functions such as assignment, copy function are not explicitly declared, C + + automatically generates these functions, usually they are by-value copies of the members, and sometimes it is meaningless or unreasonable to assign or copy objects, for example, for sockets or thread, In this case, you can explicitly tell the compiler not to generate them automatically by specifying =delete. As shown below:

class thread_guard{    std::thread& t;  Public :      Explicit thread_guard (std::thread& t_):    t (t_)    {}    ~thread_guard ()    {        if(t.joinable ())        {            t.join ();        }    }      Const&) =delete;     Thread_guardoperatorconst&) =delete;};

C + + does not automatically generate related functions such as assignment, copy function