std::basic_regex<CharT,Traits>::swap
From cppreference.com
                    
                                        
                    < cpp | regex | basic regex
                    
                                                            
                    |   void swap( basic_regex& other ) noexcept;  | 
(since C++11) | |
Exchanges the contents of two regular expressions.
Parameters
| other | - | the regular expression to swap with | 
Return value
(none)
Example
| This section is incomplete Reason: no example  | 
See also
|    (C++11)  | 
  specializes the std::swap algorithm  (function template)  |