<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>match_flag_type</title>
<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.74.0">
<link rel="home" href="../../index.html" title="Boost.Regex">
<link rel="up" href="../ref.html" title="Reference">
<link rel="prev" href="syntax_option_type/syntax_option_type_literal.html" title="Options for Literal Strings">
<link rel="next" href="error_type.html" title="error_type">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr>
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
<td align="center"><a href="../../../../../../index.html">Home</a></td>
<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="syntax_option_type/syntax_option_type_literal.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="error_type.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
</div>
<div class="section" lang="en">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_regex.ref.match_flag_type"></a><a class="link" href="match_flag_type.html" title="match_flag_type"> match_flag_type</a>
</h3></div></div></div>
<p>
The type <code class="computeroutput"><span class="identifier">match_flag_type</span></code>
is an implementation specific bitmask type (see C++ std 17.3.2.1.2) that
controls how a regular expression is matched against a character sequence.
The behavior of the format flags is described in more detail in the <a class="link" href="../format.html" title="Search and Replace Format String Syntax">format syntax guide</a>.
</p>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">regex_constants</span><span class="special">{</span>
<span class="keyword">typedef</span> <span class="identifier">implemenation</span><span class="special">-</span><span class="identifier">specific</span><span class="special">-</span><span class="identifier">bitmask</span><span class="special">-</span><span class="identifier">type</span> <span class="identifier">match_flag_type</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_default</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_not_bob</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_not_eob</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_not_bol</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_not_eol</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_not_bow</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_not_eow</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_any</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_not_null</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_continuous</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_partial</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_single_line</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_prev_avail</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_not_dot_newline</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_not_dot_null</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_posix</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_perl</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_nosubs</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">match_extra</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">format_default</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">format_sed</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">format_perl</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">format_literal</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">format_no_copy</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">format_first_only</span><span class="special">;</span>
<span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">match_flag_type</span> <span class="identifier">format_all</span><span class="special">;</span>
<span class="special">}</span> <span class="comment">// namespace regex_constants
</span><span class="special">}</span> <span class="comment">// namespace boost
</span></pre>
<a name="boost_regex.ref.match_flag_type.description"></a><h5>
<a name="id1130495"></a>
<a class="link" href="match_flag_type.html#boost_regex.ref.match_flag_type.description">Description</a>
</h5>
<p>
The type <code class="computeroutput"><span class="identifier">match_flag_type</span></code>
is an implementation specific bitmask type (see C++ std 17.3.2.1.2). When
matching a regular expression against a sequence of characters [first, last)
then setting its elements has the effects listed in the table below:
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>
<p>
Element
</p>
</th>
<th>
<p>
Effect if set
</p>
</th>
</tr></thead>
<tbody>
<tr>
<td>
<p>
match_default
</p>
</td>
<td>
<p>
Specifies that matching of regular expressions proceeds without
any modification of the normal rules used in ECMA-262, ECMAScript
Language Specification, Chapter 15 part 10, RegExp (Regular Expression)
Objects (FWD.1)
</p>
</td>
</tr>
<tr>
<td>
<p>
match_not_bob
</p>
</td>
<td>
<p>
Specifies that the expressions "\A" and "\`"
should not match against the sub-sequence [first,first).
</p>
</td>
</tr>
<tr>
<td>
<p>
match_not_eob
</p>
</td>
<td>
<p>
Specifies that the expressions "\'", "\z" and
"\Z" should not match against the sub-sequence [last,last).
</p>
</td>
</tr>
<tr>
<td>
<p>
match_not_bol
</p>
</td>
<td>
<p>
Specifies that the expression "^" should not be matched
against the sub-sequence [first,first).
</p>
</td>
</tr>
<tr>
<td>
<p>
match_not_eol
</p>
</td>
<td>
<p>
Specifies that the expression "$" should not be matched
against the sub-sequence [last,last).
</p>
</td>
</tr>
<tr>
<td>
<p>
match_not_bow
</p>
</td>
<td>
<p>
Specifies that the expressions "\<" and "\b"
should not be matched against the sub-sequence [first,first).
</p>
</td>
</tr>
<tr>
<td>
<p>
match_not_eow
</p>
</td>
<td>
<p>
Specifies that the expressions "\>" and "\b"
should not be matched against the sub-sequence [last,last).
</p>
</td>
</tr>
<tr>
<td>
<p>
match_any
</p>
</td>
<td>
<p>
Specifies that if more than one match is possible then any match
is an acceptable result: this will still find the leftmost match,
but may not find the "best" match at that position. Use
this flag if you care about the speed of matching, but don't care
what was matched (only whether there is one or not).
</p>
</td>
</tr>
<tr>
<td>
<p>
match_not_null
</p>
</td>
<td>
<p>
Specifies that the expression can not be matched against an empty
sequence.
</p>
</td>
</tr>
<tr>
<td>
<p>
match_continuous
</p>
</td>
<td>
<p>
Specifies that the expression must match a sub-sequence that begins
at first.
</p>
</td>
</tr>
<tr>
<td>
<p>
match_partial
</p>
</td>
<td>
<p>
Specifies that if no match can be found, then it is acceptable
to return a match [from, last) such that from!= last, if there
could exist some longer sequence of characters [from,to) of which
[from,last) is a prefix, and which would result in a full match.
This flag is used when matching incomplete or very long texts,
see the partial matches documentation for more information.
</p>
</td>
</tr>
<tr>
<td>
<p>
match_extra
</p>
</td>
<td>
<p>
Instructs the matching engine to retain all available capture information;
if a capturing group is repeated then information about every repeat
is available via match_results::captures() or sub_match_captures().
</p>
</td>
</tr>
<tr>
<td>
<p>
match_single_line
</p>
</td>
<td>
<p>
Equivalent to the inverse of Perl's m/ modifier; prevents ^ from
matching after an embedded newline character (so that it only matches
at the start of the text being matched), and $ from matching before
an embedded newline (so that it only matches at the end of the
text being matched).
</p>
</td>
</tr>
<tr>
<td>
<p>
match_prev_avail
</p>
</td>
<td>
<p>
Specifies that --first is a valid iterator position, when this
flag is set then the flags match_not_bol and match_not_bow are
ignored by the regular expression algorithms (RE.7) and iterators
(RE.8).
</p>
</td>
</tr>
<tr>
<td>
<p>
match_not_dot_newline
</p>
</td>
<td>
<p>
Specifies that the expression "." does not match a newline
character. This is the inverse of Perl's s/ modifier.
</p>
</td>
</tr>
<tr>
<td>
<p>
match_not_dot_null
</p>
</td>
<td>
<p>
Specifies that the expression "." does not match a character
null '\0'.
</p>
</td>
</tr>
<tr>
<td>
<p>
match_posix
</p>
</td>
<td>
<p>
Specifies that the expression should be matched according to the
POSIX <a class="link" href="../syntax/leftmost_longest_rule.html" title="The Leftmost Longest Rule">leftmost-longest
rule</a>, regardless of what kind of expression was compiled.
Be warned that these rules do not work well with many Perl-specific
features such as non-greedy repeats.
</p>
</td>
</tr>
<tr>
<td>
<p>
match_perl
</p>
</td>
<td>
<p>
Specifies that the expression should be matched according to the
<a class="link" href="../syntax/perl_syntax.html#boost_regex.syntax.perl_syntax.what_gets_matched">Perl
matching rules</a>, irrespective of what kind of expression
was compiled.
</p>
</td>
</tr>
<tr>
<td>
<p>
match_nosubs
</p>
</td>
<td>
<p>
Makes the expression behave as if it had no marked subexpressions,
no matter how many capturing groups are actually present. The
<a class="link" href="match_results.html" title="match_results"><code class="computeroutput"><span class="identifier">match_results</span></code></a>
class will only contain information about the overall match, and
not any sub-expressions.
</p>
</td>
</tr>
<tr>
<td>
<p>
format_default
</p>
</td>
<td>
<p>
Specifies that when a regular expression match is to be replaced
by a new string, that the new string is constructed using the rules
used by the ECMAScript replace function in ECMA-262, ECMAScript
Language Specification, Chapter 15 part 5.4.11 String.prototype.replace.
(FWD.1).
</p>
<p>
This is functionally identical to the <a class="link" href="../format/perl_format.html" title="Perl Format String Syntax">Perl
format string rules</a>.
</p>
<p>
In addition during search and replace operations then all non-overlapping
occurrences of the regular expression are located and replaced,
and sections of the input that did not match the expression, are
copied unchanged to the output string.
</p>
</td>
</tr>
<tr>
<td>
<p>
format_sed
</p>
</td>
<td>
<p>
Specifies that when a regular expression match is to be replaced
by a new string, that the new string is constructed using the rules
used by the Unix sed utility in IEEE Std 1003.1-2001, Portable
Operating SystemInterface (POSIX ), Shells and Utilities. See also
the <a class="link" href="../format/sed_format.html" title="Sed Format String Syntax">Sed Format string
reference</a>.
</p>
</td>
</tr>
<tr>
<td>
<p>
format_perl
</p>
</td>
<td>
<p>
Specifies that when a regular expression match is to be replaced
by a new string, that the new string is constructed using <a class="link" href="../format/perl_format.html" title="Perl Format String Syntax">the same rules as Perl
5</a>.
</p>
</td>
</tr>
<tr>
<td>
<p>
format_literal
</p>
</td>
<td>
<p>
Specifies that when a regular expression match is to be replaced
by a new string, that the new string is a literal copy of the replacement
text.
</p>
</td>
</tr>
<tr>
<td>
<p>
format_all
</p>
</td>
<td>
<p>
Specifies that all syntax extensions are enabled, including conditional
(?ddexpression1:expression2) replacements: see the <a class="link" href="../format/boost_format_syntax.html" title="Boost-Extended Format String Syntax">format
string guide</a> for more details.
</p>
</td>
</tr>
<tr>
<td>
<p>
format_no_copy
</p>
</td>
<td>
<p>
When specified during a search and replace operation, then sections
of the character container sequence being searched that do match
the regular expression, are not copied to the output string.
</p>
</td>
</tr>
<tr>
<td>
<p>
format_first_only
</p>
</td>
<td>
<p>
When specified during a search and replace operation, then only
the first occurrence of the regular expression is replaced.
</p>
</td>
</tr>
</tbody>
</table></div>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><div class="copyright-footer">Copyright © 1998 -2007 John Maddock<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
</p>
</div></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="syntax_option_type/syntax_option_type_literal.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="error_type.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
</div>
</body>
</html>
