28 Regular expressions library [re]

28.11 Regular expression algorithms [re.alg]

28.11.2 regex_match [re.alg.match]

template <class BidirectionalIterator, class Allocator, class charT, class traits> bool regex_match(BidirectionalIterator first, BidirectionalIterator last, match_results<BidirectionalIterator, Allocator>& m, const basic_regex<charT, traits>& e, regex_constants::match_flag_type flags = regex_constants::match_default);

Requires: The type BidirectionalIterator shall satisfy the requirements of a Bidirectional Iterator ([bidirectional.iterators]).

Effects: Determines whether there is a match between the regular expression e, and all of the character sequence [first,last). The parameter flags is used to control how the expression is matched against the character sequence. Returns true if such a match exists, false otherwise.

Postconditions: m.ready() == true in all cases. If the function returns false, then the effect on parameter m is unspecified except that m.size() returns 0 and m.empty() returns true. Otherwise the effects on parameter m are given in Table [tab:re:alg:match].

Table 143 — Effects of regex_match algorithm
ElementValue
m.size() 1 + e.mark_count()
m.empty() false
m.prefix().first first
m.prefix().second first
m.prefix().matched false
m.suffix().first last
m.suffix().second last
m.suffix().matched false
m[0].first first
m[0].second last
m[0].matched true
m[n].first For all integers 0 < n < m.size(), the start of the sequence that matched sub-expression n. Alternatively, if sub-expression n did not participate in the match, then last.
m[n].second For all integers 0 < n < m.size(), the end of the sequence that matched sub-expression n. Alternatively, if sub-expression n did not participate in the match, then last.
m[n].matched For all integers 0 < n < m.size(), true if sub-expression n participated in the match, false otherwise.

template <class BidirectionalIterator, class charT, class traits> bool regex_match(BidirectionalIterator first, BidirectionalIterator last, const basic_regex<charT, traits>& e, regex_constants::match_flag_type flags = regex_constants::match_default);

Effects: Behaves “as if” by constructing an instance of match_results<BidirectionalIterator> what, and then returning the result of regex_match(first, last, what, e, flags).

template <class charT, class Allocator, class traits> bool regex_match(const charT* str, match_results<const charT*, Allocator>& m, const basic_regex<charT, traits>& e, regex_constants::match_flag_type flags = regex_constants::match_default);

Returns: regex_match(str, str + char_traits<charT>::length(str), m, e, flags).

template <class ST, class SA, class Allocator, class charT, class traits> bool regex_match(const basic_string<charT, ST, SA>& s, match_results< typename basic_string<charT, ST, SA>::const_iterator, Allocator>& m, const basic_regex<charT, traits>& e, regex_constants::match_flag_type flags = regex_constants::match_default);

Returns: regex_match(s.begin(), s.end(), m, e, flags).

template <class charT, class traits> bool regex_match(const charT* str, const basic_regex<charT, traits>& e, regex_constants::match_flag_type flags = regex_constants::match_default);

Returns: regex_match(str, str + char_traits<charT>::length(str), e, flags)

template <class ST, class SA, class charT, class traits> bool regex_match(const basic_string<charT, ST, SA>& s, const basic_regex<charT, traits>& e, regex_constants::match_flag_type flags = regex_constants::match_default);

Returns: regex_match(s.begin(), s.end(), e, flags).