std::regex_constants::match_flag_type

 

C++

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Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

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Ranges library (C++20)

Algorithms library

Numerics library

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Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

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Technical Specifications

 

Regular expressions library

Classes

basic_regex (C++11)

sub_match (C++11)

match_results (C++11)

Algorithms

regex_match (C++11)

regex_search (C++11)

regex_replace (C++11)

Iterators

regex_iterator (C++11)

regex_token_iterator (C++11)

Exceptions

regex_error (C++11)

Traits

regex_traits (C++11)

Constants

syntax_option_type (C++11)

match_flag_type (C++11)

error_type (C++11)

Regex Grammar

Modified ECMAScript-262 (C++11)

 

Defined in header <regex>
typedef /*unspecified*/ match_flag_type;		(since C++11)
constexpr match_flag_type match_default = 0; constexpr match_flag_type match_not_bol = /*unspecified*/; constexpr match_flag_type match_not_eol = /*unspecified*/; constexpr match_flag_type match_not_bow = /*unspecified*/; constexpr match_flag_type match_not_eow = /*unspecified*/; constexpr match_flag_type match_any = /*unspecified*/; constexpr match_flag_type match_not_null = /*unspecified*/; constexpr match_flag_type match_continuous = /*unspecified*/; constexpr match_flag_type match_prev_avail = /*unspecified*/; constexpr match_flag_type format_default = 0; constexpr match_flag_type format_sed = /*unspecified*/; constexpr match_flag_type format_no_copy = /*unspecified*/; constexpr match_flag_type format_first_only = /*unspecified*/;		(since C++11) (until C++17)
inline constexpr match_flag_type match_default = 0; inline constexpr match_flag_type match_not_bol = /*unspecified*/; inline constexpr match_flag_type match_not_eol = /*unspecified*/; inline constexpr match_flag_type match_not_bow = /*unspecified*/; inline constexpr match_flag_type match_not_eow = /*unspecified*/; inline constexpr match_flag_type match_any = /*unspecified*/; inline constexpr match_flag_type match_not_null = /*unspecified*/; inline constexpr match_flag_type match_continuous = /*unspecified*/; inline constexpr match_flag_type match_prev_avail = /*unspecified*/; inline constexpr match_flag_type format_default = 0; inline constexpr match_flag_type format_sed = /*unspecified*/; inline constexpr match_flag_type format_no_copy = /*unspecified*/; inline constexpr match_flag_type format_first_only = /*unspecified*/;		(since C++17)

match_flag_type is a BitmaskType that specifies additional regular expression matching options.

Constants

Note: [first, last) refers to the character sequence being matched.

Constant	Explanation
match_not_bol	The first character in [first,last) will be treated as if it is not at the beginning of a line (i.e. ^ will not match [first,first)
match_not_eol	The last character in [first,last) will be treated as if it is not at the end of a line (i.e. $ will not match [last,last)
match_not_bow	"\b" will not match [first,first)
match_not_eow	"\b" will not match [last,last)
match_any	If more than one match is possible, then any match is an acceptable result
match_not_null	Do not match empty sequences
match_continuous	Only match a sub-sequence that begins at first
match_prev_avail	--first is a valid iterator position. When set, causes match_not_bol and match_not_bow to be ignored
format_default	Use ECMAScript rules to construct strings in std::regex_replace (syntax documentation)
format_sed	Use POSIX sed utility rules in std::regex_replace. (syntax documentation)
format_no_copy	Do not copy un-matched strings to the output in std::regex_replace
format_first_only	Only replace the first match in std::regex_replace

All constants, except for match_default and format_default, are bitmask elements. The match_default and format_default constants are empty bitmasks

Notes

In C++11, these constants were specified with redundant keyword static, which was removed by C++14 via LWG issue 2053

See also

regex_match (C++11)	attempts to match a regular expression to an entire character sequence (function template)
syntax_option_type (C++11)	general options controlling regex behavior (typedef)
error_type (C++11)	describes different types of matching errors (typedef)