std::sub_match

From Cppreference

C++ Standard Library
Language Utilities library Strings library Containers library Algorithms library Iterators library Numerics library Input/output library Localizations library Regular expressions library (C++11) Atomic operations library (C++11) Thread support library (C++11)
Regular expressions library
Classes basic_regex (C++11) sub_match (C++11) match_results (C++11) Algorithms regex_match (C++11) regex_search (C++11) regex_replace (C++11) Iterators regex_iterator (C++11) regex_token_iterator (C++11) Exceptions regex_error (C++11) Traits regex_traits (C++11) Constants syntax_option_type (C++11) match_flag_type (C++11) error_type (C++11)
std::sub_match
Member functions sub_match::sub_match (C++11) sub_match::length (C++11) sub_match::str sub_match::operator string_type (C++11) sub_match::compare (C++11) Non-member functions operator== operator!= operator<< operator<= operator> operator>= (C++11)

Defined in header <regex>
template<     class BidirectionalIterator > class sub_match;		(since C++11)

The class template sub_match is used by the regular expression engine to denote sequences of characters matched by marked sub-expressions. A match is a [begin, end) pair within the target range matched by the regular expression, but with additional observer functions to enhance code clarity.

Only the default constructor is publicly accessible: object of this class are normally constructed and populated as a part of a std::match_results container during the processing of one of the regex algorithms.

The member functions return defined default values unless the matched member is true.

Inherits std::pair<BidirectionalIterator, BidirectionalIterator>, although this type can not be treated as a std::pair object because member functions such as swap and assignment will not work as expected.

Several specializations for common character sequence types are provided:

Defined in header <regex>
Type	Definition
csub_match	sub_match<const char*>
wcsub_match	sub_match<const wchar_t*>
ssub_match	sub_match<std::string::const_iterator>
wssub_match	sub_match<std::wstring::const_iterator>

Contents 1 Member types 2 Member objects 3 Inherited from std::pair 3.1 Member functions 3.1.1 Observers 3.2 Non-member functions

[edit] Member types

Member type	Definition
iterator	BidirectionalIterator
value_type	std::iterator_traits<BidirectionalIterator>::value_type
difference_type	std::iterator_traits<BidirectionalIterator>::difference_type
string_type	std::basic_string<value_type>

[edit] Member objects

matched	Indicates if this match was successful.

[edit] Member functions

(constructor)	constructs the match object (public member function)
Observers
length	Returns the length of the match (if any). (public member function)
str operator string_type	Converts to the underlying string type. (public member function)
compare	Compares matched subsequence (if any). (public member function)

[edit] Non-member functions

operator== operator!= operator< operator<= operator> operator>=	lexicographically compares the values in the container (function)