[header][other] regex (C++11)

*[header][other] regex (C++11)

<regex>

Regular Expressions

Regular expressions are a standardized way to express patterns to be matched against sequences of characters.

The standard C++ library provides support for regular expressions in the <regex> header through a series of operations. All these operations make use of some typical regex parameters:

• Target sequence (subject): The sequence of characters searched for the pattern. Generally, this is a range specified by two iterators, but some functions also accept a c-string or a string object instead.
• Regular expression (pattern): The pattern which is searched for in the target sequence. This must be an object of a basic_regex type (such as regex), generally constructed from a string with a special syntax that describes what constitutes a match (see ECMAScript syntax).
• Matches array: Some operations allow to retrieve information about matches. This information is stored in one of the special match_results array types (such as cmatch or smatch).
• Replacement string: Some operations can replace matches. These replacements are specified in strings that allow for a special format (see ECMAScript syntax).

Regex operations

Regex operations are performed using either functions or special iterator adaptors:

Functions:

regex_match

Match sequence (function template )

regex_search

Search sequence (function template )

regex_replace

Replace matched sequence (function template )

Iterator types:

regex_iterator

Regex iterator (class template )

regex_token_iterator

Regex token iterator (class template )

Classes

The regex functions and iterators make heavy use of a set of supporting types as arguments and return values:

Basic types:

basic_regex

Regular expression (class template )

match_results

Match results (class template )

sub_match

Sub-expression match (class template )

regex_traits

Regex traits (class template )

regex_error

Regex exception (class )

Some of these types are templates, and have aliases for their most common instantiations:

basic_regex instantiations:

regex

Regex (class )

wregex

Regex for wchar_t (class )

match_results instantiations:

cmatch

match_results for string literals (class )

wcmatch

match_results for wide string literals (class )

smatch

match_results for string objects (class )

wsmatch

match_results for wide string objects (class )

sub_match instantiations:

csub_match

sub_match for string literals (class )

wcsub_match

sub_match for wide string literals (class )

ssub_match

sub_match for strings (class )

wssub_match

sub_match for wide strings (class )

Namespaces

This header also defines a namespace, regex_constants, under which all constant values to be used by the library are located:

regex_constants

regex constants (namespace )

Grammar

Regular expressions follow very strict grammars. By default, the functions in this library use the ECMAScript grammar:

ECMAScript syntax

ECMAScript regular expressions pattern syntax (syntax specifications )

Other functions

begin

Iterator to beginning (function template )

end

Iterator to end (function template )

내용 출처 : http://www.cplusplus.com/reference/regex/