std::error_code::assign
From cppreference.com
                    
                                        
                    < cpp | error | error code
                    
                                                            
                    |   void assign( int ec, const error_category& ecat );  | 
(since C++11) | |
Replaces the contents with error code ec and corresponding category ecat.
Contents | 
[edit] Parameters
| ec | - | platform-dependent error code enum to assign | 
| ecat | - |   error category corresponding to ec
 | 
[edit] Return value
(none)
[edit] Exceptions
[edit] See also
|    assigns another error code  (public member function)  | |