std::regex_error::code
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                    < cpp | regex | regex error
                    
                                                            
                    |   Defined in header  <regex>
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|   std::regex_constants::error_type code() const;  | 
(since C++11) | |
Returns the std::regex_constants::error_type that was passed to the std::regex_error constructor.
See Also
|    (C++11)  | 
   describes different types of matching errors   (typedef)  | 
  constructs a regex_error object (public member function)  |