std::regex_traits
Defined in header <regex> | ||
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template< class CharT > class regex_traits; | (since C++11) |
The type trait template regex_traits supplies std::basic_regex with the set of types and functions necessary to operate on the type CharT.
Since many of regex operations are locale-sensitive (when std::regex_constants::collate flag is set), the regex_traits class typically holds an instance of a std::locale as a private member.
Standard specializations
Two specializations of std::regex_traits are defined by the standard library:
std::regex_traits<char> |
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std::regex_traits<wchar_t> |
These specializations make it possible to use std::basic_regex<char> (aka std::regex) and std::basic_regex<wchar_t> (aka std::wregex). To use std::basic_regex with other character types (for example, char32_t), a user-provided trait class must be used.
Member types
| Type | Definition |
|---|---|
char_type |
CharT |
string_type |
std::basic_string<CharT> |
locale_type | The locale used for localized behavior in the regular expression. Must be CopyConstructible |
char_class_type | Represents a character classification and is capable of holding an implementation specific set returned by lookup_classname. Must be a BitmaskType. |
Member functions
| constructs the regex_traits object (public member function) |
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[static] | calculates the length of a null-terminated character string (public static member function) |
| determines the equivalence key for a character (public member function) |
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| determines the case-insensitive equivalence key for a character (public member function) |
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| determines the sort key for the given string, used to provide collation order (public member function) |
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| determines the primary sort key for the character sequence, used to determine equivalence class (public member function) |
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| gets a collation element by name (public member function) |
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| gets a character class by name (public member function) |
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| indicates membership in a localized character class (public member function) |
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| translates the character representing a numeric digit into an integral value (public member function) |
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| sets the locale (public member function) |
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| gets the locale (public member function) |
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https://en.cppreference.com/cpp/regex/regex_traits
