std::regex_constants:: match_flag_type
|
Defined in header
<regex>
|
||
|
using
match_flag_type
=
/* implementation-defined */
;
|
(1) | (since C++11) |
|
constexpr
match_flag_type match_default
=
{
}
;
constexpr
match_flag_type match_not_bol
=
/* unspecified */
;
|
(2) |
(since C++11)
(inline since C++17) |
Constants
Note:
[
first
,
last
)
refers to the character sequence being matched.
| Name | 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.
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 2053 | C++11 |
1. the constants were declared
static
2.
match_default
and
format_default
were initialized from
0
|
1. removed the
static
specifier
2. initialized from { } |
See also
|
(C++11)
|
attempts to match a regular expression to an entire character sequence
(function template) |
|
(C++11)
|
general options controlling regex behavior
(typedef) |
|
(C++11)
|
describes different types of matching errors
(typedef) |