30 Regular expressions library [re]

30.7 Class template basic_­regex [re.regex]

30.7.1 General [re.regex.general]

For a char-like type charT, specializations of class template basic_­regex represent regular expressions constructed from character sequences of charT characters.
In the rest of [re.regex], charT denotes a given char-like type.
Storage for a regular expression is allocated and freed as necessary by the member functions of class basic_­regex.
Objects of type specialization of basic_­regex are responsible for converting the sequence of charT objects to an internal representation.
It is not specified what form this representation takes, nor how it is accessed by algorithms that operate on regular expressions.
[Note 1:
Implementations will typically declare some function templates as friends of basic_­regex to achieve this.
— end note]
The functions described in [re.regex] report errors by throwing exceptions of type regex_­error.
namespace std { template<class charT, class traits = regex_traits<charT>> class basic_regex { public: // types using value_type = charT; using traits_type = traits; using string_type = typename traits::string_type; using flag_type = regex_constants::syntax_option_type; using locale_type = typename traits::locale_type; // [re.synopt], constants static constexpr flag_type icase = regex_constants::icase; static constexpr flag_type nosubs = regex_constants::nosubs; static constexpr flag_type optimize = regex_constants::optimize; static constexpr flag_type collate = regex_constants::collate; static constexpr flag_type ECMAScript = regex_constants::ECMAScript; static constexpr flag_type basic = regex_constants::basic; static constexpr flag_type extended = regex_constants::extended; static constexpr flag_type awk = regex_constants::awk; static constexpr flag_type grep = regex_constants::grep; static constexpr flag_type egrep = regex_constants::egrep; static constexpr flag_type multiline = regex_constants::multiline; // [re.regex.construct], construct/copy/destroy basic_regex(); explicit basic_regex(const charT* p, flag_type f = regex_constants::ECMAScript); basic_regex(const charT* p, size_t len, flag_type f = regex_constants::ECMAScript); basic_regex(const basic_regex&); basic_regex(basic_regex&&) noexcept; template<class ST, class SA> explicit basic_regex(const basic_string<charT, ST, SA>& s, flag_type f = regex_constants::ECMAScript); template<class ForwardIterator> basic_regex(ForwardIterator first, ForwardIterator last, flag_type f = regex_constants::ECMAScript); basic_regex(initializer_list<charT> il, flag_type f = regex_constants::ECMAScript); ~basic_regex(); // [re.regex.assign], assign basic_regex& operator=(const basic_regex& e); basic_regex& operator=(basic_regex&& e) noexcept; basic_regex& operator=(const charT* p); basic_regex& operator=(initializer_list<charT> il); template<class ST, class SA> basic_regex& operator=(const basic_string<charT, ST, SA>& s); basic_regex& assign(const basic_regex& e); basic_regex& assign(basic_regex&& e) noexcept; basic_regex& assign(const charT* p, flag_type f = regex_constants::ECMAScript); basic_regex& assign(const charT* p, size_t len, flag_type f = regex_constants::ECMAScript); template<class ST, class SA> basic_regex& assign(const basic_string<charT, ST, SA>& s, flag_type f = regex_constants::ECMAScript); template<class InputIterator> basic_regex& assign(InputIterator first, InputIterator last, flag_type f = regex_constants::ECMAScript); basic_regex& assign(initializer_list<charT>, flag_type f = regex_constants::ECMAScript); // [re.regex.operations], const operations unsigned mark_count() const; flag_type flags() const; // [re.regex.locale], locale locale_type imbue(locale_type loc); locale_type getloc() const; // [re.regex.swap], swap void swap(basic_regex&); }; template<class ForwardIterator> basic_regex(ForwardIterator, ForwardIterator, regex_constants::syntax_option_type = regex_constants::ECMAScript) -> basic_regex<typename iterator_traits<ForwardIterator>::value_type>; }