62     struct Arg {  in test()  struct
63       Arg()           = default;  in test()
64       Arg(const Arg&) = default;  in test()
65       Arg(Arg&)       = delete;  in test()
68     Arg x;  in test()
69     auto f = std::bind_back([](const Arg&) {}, x);  in test()  argument
75     struct Arg {  in test()  struct
76       Arg()           = default;  in test()
77       Arg(const Arg&) = default;  in test()
78       Arg(Arg&&)      = delete;  in test()
81     Arg x;  in test()
82     auto f = std::bind_back([](Arg&) {}, x);  in test()  argument