prog.cpp: In instantiation of ‘void foo::invoke(int, Args&& ...) [with Args = {std::reference_wrapper<int>}]’:
prog.cpp:29:28: required from here
prog.cpp:16:25: error: could not convert ‘bound’ from ‘std::_Bind<std::_Mem_fn<void (foo::*)(int, std::reference_wrapper<int>&)>(foo*, std::_Placeholder<1>, std::reference_wrapper<int>)>’ to ‘std::function<void(int)>’
third_party(n, bound);
^