[re.submatch.general]

# 28 Text processing library [[text]](./#text)

## 28.6 Regular expressions library [[re]](re#submatch.general)

### 28.6.8 Class template sub_match [[re.submatch]](re.submatch#general)

#### 28.6.8.1 General [re.submatch.general]

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L10835)

Class template sub_match denotes the sequence of characters matched
by a particular marked sub-expression[.](#1.sentence-1)

namespace std {template<class BidirectionalIterator>class sub_match : public pair<BidirectionalIterator, BidirectionalIterator> {public:using value_type =typename iterator_traits<BidirectionalIterator>::value_type; using difference_type =typename iterator_traits<BidirectionalIterator>::difference_type; using iterator = BidirectionalIterator; using string_type = basic_string<value_type>; bool matched; constexpr sub_match();

 difference_type length() const; operator string_type() const;
 string_type str() const; int compare(const sub_match& s) const; int compare(const string_type& s) const; int compare(const value_type* s) const; void swap(sub_match& s) noexcept(*see below*); };}