Syntax ' c-char ' (1) u8 ' c-char ' (2) (since C++17) u ' c-char ' (3) (since C++11) U ' c-char ' (4) (since C++11) L ' c-char ' (5) ' c-char-sequence ' (6) where. c-char is either a character from the basic source character set minus single-quote ('), backslash (\), or the newline character, escape sequence, as defined in escape sequences universal character name, as defined in escape sequences c-char-sequence is a sequence of two or more c-cha

size_type max_size() const; (since C++11) Returns the maximum number of submatches the match_results type is able to hold due to system or library implementation limitations, i.e. std::distance(begin(), end()) for the largest number of submatches. Parameters (none). Return value Maximum number of submatches. Exceptions noexcept specification: noexcept Complexity Constant.

result_type min() const; (since C++11) Returns the minimum value potentially generated by the distribution. Parameters (none). Return value The minimum value potentially generated by the distribution. Complexity Constant. See also max returns the maximum potentially generated value (public member function)

const_reference prefix() const; (since C++11) Obtains a reference to the std::sub_match object representing the target sequence between the start of the beginning of the target sequence and the start of the entire match of the regular expression. The behavior is undefined unless ready() == true. Parameters (none). Return value Reference to the unmatched prefix. Example #include <iostream> #include <regex> #include <string> int main() { std::regex re("a(a

bool ready() const; (since C++11) Indicates if the match results are ready (valid) or not. A default-constructed match result has no result state (is not ready), and can only be made ready by one of the regex algorithms. The ready state implies that all match results have been fully established. The result of calling most member functions of the match_results object that is not ready is undefined. Return value true if the match results are ready, false otherwise. Example #includ

locale_type getloc() const; (since C++11) Returns the current locale of the traits object. If imbue() has been never called for this object, then the global locale at the time of the call is returned. Otherwise, the locale passed to the last call to imbue() is returned. Parameters (none). Return value The current locale of the traits object. Example See also imbue sets the locale (public member function)

size_type count( const Key& key ) const; (1) template< class K > size_type count( const K& x ) const; (2) (since C++14) 1) Returns the number of elements with key key, which is either 1 or 0 since this container does not allow duplicates 2) Returns the number of elements with key that compares equivalent to the value x. This overload only participates in overload resolution if the qualified-id Compare::is_transparent is valid and denotes a type. They allow calling

std::pair<iterator,iterator> equal_range( const Key& key ); (1) std::pair<const_iterator,const_iterator> equal_range( const Key& key ) const; (2) template< class K > std::pair<iterator,iterator> equal_range( const K& x ); (3) (since C++14) template< class K > std::pair<const_iterator,const_iterator> equal_range( const K& x ) const; (4) (since C++14) Returns a range containing all elements with the given key in the con

key_compare key_comp() const; Returns the function object that compares the keys, which is a copy of this container's constructor argument comp. Parameters (none). Return value The key comparison function object. Complexity Constant. See also value_comp returns the function that compares keys in objects of type value_type (public member function)

std::pair<iterator,iterator> equal_range( const Key& key ); (1) std::pair<const_iterator,const_iterator> equal_range( const Key& key ) const; (2) template< class K > std::pair<iterator,iterator> equal_range( const K& x ); (3) (since C++14) template< class K > std::pair<const_iterator,const_iterator> equal_range( const K& x ) const; (4) (since C++14) Returns a range containing all elements with the given key in the con