std::basic_regex
From cppreference.com
                    
                                        
                    
                    
                                                            
                    | Defined in header  <regex> | ||
| template <     class CharT = char, | (since C++11) | |
The class template basic_regex provides a general framework for holding regular expressions. 
Several specializations for common character types are provided:
| Defined in header  <regex> | |
| Type | Definition | 
| regex | basic_regex<char> | 
| wregex | basic_regex<wchar_t> | 
| Contents | 
[edit] Member types
| Member type | Definition | 
| value_type | CharT | 
| traits_type | Traits | 
| string_type | Traits::string_type | 
| locale_type | Traits::locale_type | 
| flag_type | std::regex_constants::syntax_option_type | 
[edit] Member functions
| constructs the regex object (public member function) | |
| destructs the regex object (public member function) | |
| assigns the contents (public member function) | |
| assigns the contents (public member function) | |
| Observers | |
| returns the number of marked sub-expressions within the regular expression (public member function) | |
| returns the syntax flags (public member function) | |
| Locale | |
| get locale information (public member function) | |
| set locale information (public member function) | |
| Modifiers | |
| swaps the contents (public member function) | |
| Constants | |
| Value | Effect(s) | 
| icase | ignores case when matching characters | 
| nosubs | does not store sub-expression matches | 
| optimize | faster matching, slower construction | 
| collate | makes range expressions locale-sensitive | 
| ECMAScript | uses an ECMA-262 (Perl 5) syntax | 
| basic | uses a POSIX basic regular expression syntax | 
| extended | uses a POSIX extended regular expression syntax | 
| awk | uses an awk-compatible syntax | 
| grep | uses a grep-compatible syntax | 
| egrep | uses an extended grep-compatible syntax | 
[edit] Non-member functions
| (C++11) | specializes the std::swap algorithm (function template) |