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<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="error_type.html" title="cpp/regex/error type"><span class="t-lines"><span>error_type</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div></div></td></tr>
<tr class="t-nv-h1"><td colspan="5"> Regex Grammar</td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="ecmascript.html" title="cpp/regex/ecmascript"><span class="t-lines"><span>Modified ECMAScript-262</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div></div></td></tr>
</table></div><div><span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/regex/navbar_content&action=edit">[edit]</a></span></div></div></div></div><div class="t-navbar-sep"> </div><div class="t-navbar-head"><strong class="selflink"><tt>std::regex_traits</tt></strong><div class="t-navbar-menu"><div><div><table class="t-nv-begin" cellpadding="0" style="">
<tr class="t-nv-h1"><td colspan="5"> Member Functions</td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="regex_traits/regex_traits.html" title="cpp/regex/regex traits/regex traits"><span class="t-lines"><span>regex_traits::regex_traits</span></span></a></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="regex_traits/length.html" title="cpp/regex/regex traits/length"><span class="t-lines"><span>regex_traits::length</span></span></a></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="regex_traits/translate.html" title="cpp/regex/regex traits/translate"><span class="t-lines"><span>regex_traits::translate</span></span></a></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="regex_traits/translate_nocase.html" title="cpp/regex/regex traits/translate nocase"><span class="t-lines"><span>regex_traits::translate_nocase</span></span></a></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="regex_traits/transform.html" title="cpp/regex/regex traits/transform"><span class="t-lines"><span>regex_traits::transform</span></span></a></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="regex_traits/transform_primary.html" title="cpp/regex/regex traits/transform primary"><span class="t-lines"><span>regex_traits::transform_primary</span></span></a></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="regex_traits/lookup_collatename.html" title="cpp/regex/regex traits/lookup collatename"><span class="t-lines"><span>regex_traits::lookup_collatename</span></span></a></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="regex_traits/lookup_classname.html" title="cpp/regex/regex traits/lookup classname"><span class="t-lines"><span>regex_traits::lookup_classname</span></span></a></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="regex_traits/isctype.html" title="cpp/regex/regex traits/isctype"><span class="t-lines"><span>regex_traits::isctype</span></span></a></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="regex_traits/value.html" title="cpp/regex/regex traits/value"><span class="t-lines"><span>regex_traits::value</span></span></a></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="regex_traits/imbue.html" title="cpp/regex/regex traits/imbue"><span class="t-lines"><span>regex_traits::imbue</span></span></a></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="regex_traits/getloc.html" title="cpp/regex/regex traits/getloc"><span class="t-lines"><span>regex_traits::getloc</span></span></a></div></div></td></tr>
</table></div><div><span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/regex/regex_traits/navbar_content&action=edit">[edit]</a></span></div></div></div></div><div class="t-navbar-sep"> </div></div>
<table class="t-dcl-begin"><tbody>
<tr class="t-dsc-header">
<td> <div>Defined in header <code><a href="../header/regex.html" title="cpp/header/regex"><regex></a></code>
</div></td>
<td></td>
<td></td>
</tr>
<tr class="t-dcl t-since-cxx11">
<td> <div><span class="mw-geshi cpp source-cpp"><span class="kw1">template</span><span class="sy1"><</span> <span class="kw1">class</span> CharT <span class="sy1">></span><br />
<span class="kw1">class</span> regex_traits<span class="sy4">;</span></span></div></td>
<td class="t-dcl-nopad"> </td>
<td> <span class="t-mark-rev t-since-cxx11">(since C++11)</span> </td>
</tr>
<tr class="t-dcl-sep"><td></td><td></td><td></td></tr>
</tbody></table>
<p>The type trait template <code>regex_traits</code> supplies <span class="t-lc">std::basic_regex</span> with the set of types and functions necessary to operate on the type <code>CharT</code>.
</p><p>Since many of regex operations are locale-sensitive (when <span class="t-lc">std::regex_constants::collate</span> flag is set), the regex_traits class typically holds an instance of a <span class="t-lc">std::locale</span> as a private member.
</p>
<h3><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=cpp/regex/regex_traits&action=edit&section=1" title="Edit section: Standard specializations">edit</a>]</span> <span class="mw-headline" id="Standard_specializations">Standard specializations</span></h3>
<p>Two specializations of <code>std::regex_traits</code> are defined by the standard library:
</p>
<table class="t-dsc-begin">
<tr class="t-dsc">
<td colspan="2"> <code>std::regex_traits<char></code>
</td></tr>
<tr class="t-dsc">
<td colspan="2"> <code>std::regex_traits<wchar_t></code>
</td></tr>
</table>
<p>These specializations make it possible to use <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="basic_regex.html"><span class="kw1723">std::<span class="me2">basic_regex</span></span></a><span class="sy1"><</span><span class="kw4">char</span><span class="sy1">></span></span></span> (aka <span class="t-lc">std::regex</span>) and <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="basic_regex.html"><span class="kw1723">std::<span class="me2">basic_regex</span></span></a><span class="sy1"><</span><span class="kw4">wchar_t</span><span class="sy1">></span></span></span> (aka <span class="t-lc">std::wregex</span>), but in order to use, for example, <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="basic_regex.html"><span class="kw1723">std::<span class="me2">basic_regex</span></span></a><span class="sy1"><</span><span class="kw4">char32_t</span><span class="sy1">></span></span></span>, user-provided specializtion <span class="t-c"><span class="mw-geshi cpp source-cpp">std<span class="sy4">::</span><span class="me2">regex_traits</span><span class="sy1"><</span><span class="kw4">char32_t</span><span class="sy1">></span></span></span> needs to be defined.
</p>
<h3><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=cpp/regex/regex_traits&action=edit&section=2" title="Edit section: Member types">edit</a>]</span> <span class="mw-headline" id="Member_types">Member types</span></h3>
<table class="t-dsc-begin">
<tr class="t-dsc-hitem">
<td> Type
</td>
<td> Definition
</td></tr>
<tr class="t-dsc">
<td> <code>char_type</code>
</td>
<td> <code>CharT</code>
</td></tr>
<tr class="t-dsc">
<td> <code>string_type</code>
</td>
<td> <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="../string/basic_string.html"><span class="kw1070">std::<span class="me2">basic_string</span></span></a><span class="sy1"><</span>CharT<span class="sy1">></span></span></span>
</td></tr>
<tr class="t-dsc">
<td> <code>locale_type</code>
</td>
<td> The locale used for localized behavior in the regular expression. Must be <a href="../concept/CopyConstructible.html" title="cpp/concept/CopyConstructible"><code>CopyConstructible</code></a>
</td></tr>
<tr class="t-dsc">
<td> <code>char_class_type</code>
</td>
<td> Represents a character classification and is capable of holding an implementation specific set returned by <code>lookup_classname</code>. Must be a <a href="../concept/BitmaskType.html" title="cpp/concept/BitmaskType"><code>BitmaskType</code></a>.
</td></tr>
</table>
<h3><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=cpp/regex/regex_traits&action=edit&section=3" title="Edit section: Member functions">edit</a>]</span> <span class="mw-headline" id="Member_functions">Member functions</span></h3>
<table class="t-dsc-begin">
<tr class="t-dsc">
<td> <div class="t-dsc-member-div t-dsc-member-nobold-div"><div><a href="regex_traits/regex_traits.html" title="cpp/regex/regex traits/regex traits"> <span class="t-lines"><span>(constructor)</span></span></a></div></div>
</td>
<td> constructs the regex_traits object <br /> <span class="t-mark">(public member function)</span> <span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/regex/regex_traits/dsc_constructor&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="regex_traits/length.html" title="cpp/regex/regex traits/length"> <span class="t-lines"><span>length</span></span></a></div><div><span class="t-lines"><span><span class="t-cmark">[static]</span></span></span></div></div>
</td>
<td> calculates the length of a null-terminated character string <br /> <span class="t-mark">(public static member function)</span> <span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/regex/regex_traits/dsc_length&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="regex_traits/translate.html" title="cpp/regex/regex traits/translate"> <span class="t-lines"><span>translate</span></span></a></div></div>
</td>
<td> determines the equivalence key for a character <br /> <span class="t-mark">(public member function)</span> <span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/regex/regex_traits/dsc_translate&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="regex_traits/translate_nocase.html" title="cpp/regex/regex traits/translate nocase"> <span class="t-lines"><span>translate_nocase</span></span></a></div></div>
</td>
<td> determines the case-insensitive equivalence key for a character <br /> <span class="t-mark">(public member function)</span> <span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/regex/regex_traits/dsc_translate_nocase&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="regex_traits/transform.html" title="cpp/regex/regex traits/transform"> <span class="t-lines"><span>transform</span></span></a></div></div>
</td>
<td> determines the sort key for the given string, used to provide collation order <br /> <span class="t-mark">(public member function)</span> <span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/regex/regex_traits/dsc_transform&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="regex_traits/transform_primary.html" title="cpp/regex/regex traits/transform primary"> <span class="t-lines"><span>transform_primary</span></span></a></div></div>
</td>
<td> determines the primary sort key for the character sequence, used to determine equivalence class <br /> <span class="t-mark">(public member function)</span> <span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/regex/regex_traits/dsc_transform_primary&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="regex_traits/lookup_collatename.html" title="cpp/regex/regex traits/lookup collatename"> <span class="t-lines"><span>lookup_collatename</span></span></a></div></div>
</td>
<td> gets a collation element by name <br /> <span class="t-mark">(public member function)</span> <span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/regex/regex_traits/dsc_lookup_collatename&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="regex_traits/lookup_classname.html" title="cpp/regex/regex traits/lookup classname"> <span class="t-lines"><span>lookup_classname</span></span></a></div></div>
</td>
<td> gets a character class by name <br /> <span class="t-mark">(public member function)</span> <span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/regex/regex_traits/dsc_lookup_classname&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="regex_traits/isctype.html" title="cpp/regex/regex traits/isctype"> <span class="t-lines"><span>isctype</span></span></a></div></div>
</td>
<td> indicates membership in a localized character class <br /> <span class="t-mark">(public member function)</span> <span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/regex/regex_traits/dsc_isctype&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="regex_traits/value.html" title="cpp/regex/regex traits/value"> <span class="t-lines"><span>value</span></span></a></div></div>
</td>
<td> translates the character representing a numeric digit into an integral value <br /> <span class="t-mark">(public member function)</span> <span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/regex/regex_traits/dsc_value&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="regex_traits/imbue.html" title="cpp/regex/regex traits/imbue"> <span class="t-lines"><span>imbue</span></span></a></div></div>
</td>
<td> sets the locale <br /> <span class="t-mark">(public member function)</span> <span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/regex/regex_traits/dsc_imbue&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="regex_traits/getloc.html" title="cpp/regex/regex traits/getloc"> <span class="t-lines"><span>getloc</span></span></a></div></div>
</td>
<td> gets the locale <br /> <span class="t-mark">(public member function)</span> <span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/regex/regex_traits/dsc_getloc&action=edit">[edit]</a></span>
</td></tr>
</table>
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