Add support for named sub-expressions.

[SVN r52823]

doc/html/boost_regex/syntax/basic_extended.html

@@ -28,7 +28,7 @@
       Expression Syntax</a>
 </h3></div></div></div>
 <a name="boost_regex.syntax.basic_extended.synopsis"></a><h4>
-<a name="id791861"></a>
+<a name="id789119"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.synopsis">Synopsis</a>
       </h4>
 <p>
@@ -46,7 +46,7 @@
 <a name="boost_regex.posix_extended_syntax"></a><p>
       </p>
 <a name="boost_regex.syntax.basic_extended.posix_extended_syntax"></a><h4>
-<a name="id792040"></a>
+<a name="id789298"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.posix_extended_syntax">POSIX
         Extended Syntax</a>
       </h4>
@@ -56,7 +56,7 @@
       </p>
 <pre class="programlisting">.[{()\*+?|^$</pre>
 <a name="boost_regex.syntax.basic_extended.wildcard_"></a><h5>
-<a name="id792062"></a>
+<a name="id789319"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.wildcard_">Wildcard:</a>
       </h5>
 <p>
@@ -74,7 +74,7 @@
         </li>
 </ul></div>
 <a name="boost_regex.syntax.basic_extended.anchors_"></a><h5>
-<a name="id792106"></a>
+<a name="id789364"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.anchors_">Anchors:</a>
       </h5>
 <p>
@@ -86,7 +86,7 @@
         of an expression, or the last character of a sub-expression.
       </p>
 <a name="boost_regex.syntax.basic_extended.marked_sub_expressions_"></a><h5>
-<a name="id792129"></a>
+<a name="id789386"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.marked_sub_expressions_">Marked
         sub-expressions:</a>
       </h5>
@@ -98,7 +98,7 @@
         to by a back-reference.
       </p>
 <a name="boost_regex.syntax.basic_extended.repeats_"></a><h5>
-<a name="id792163"></a>
+<a name="id789420"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.repeats_">Repeats:</a>
       </h5>
 <p>
@@ -184,7 +184,7 @@ cab
         operator to be applied to.
       </p>
 <a name="boost_regex.syntax.basic_extended.back_references_"></a><h5>
-<a name="id792469"></a>
+<a name="id789726"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.back_references_">Back references:</a>
       </h5>
 <p>
@@ -214,7 +214,7 @@ cab
         </p></td></tr>
 </table></div>
 <a name="boost_regex.syntax.basic_extended.alternation"></a><h5>
-<a name="id792532"></a>
+<a name="id789790"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.alternation">Alternation</a>
       </h5>
 <p>
@@ -227,7 +227,7 @@ cab
         will match either of "abd" or "abef".
       </p>
 <a name="boost_regex.syntax.basic_extended.character_sets_"></a><h5>
-<a name="id792599"></a>
+<a name="id789857"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.character_sets_">Character
         sets:</a>
       </h5>
@@ -240,7 +240,7 @@ cab
         A bracket expression may contain any combination of the following:
       </p>
 <a name="boost_regex.syntax.basic_extended.single_characters_"></a><h6>
-<a name="id792620"></a>
+<a name="id789877"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.single_characters_">Single
         characters:</a>
       </h6>
@@ -249,7 +249,7 @@ cab
         or 'c'.
       </p>
 <a name="boost_regex.syntax.basic_extended.character_ranges_"></a><h6>
-<a name="id792651"></a>
+<a name="id789908"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.character_ranges_">Character
         ranges:</a>
       </h6>
@@ -265,7 +265,7 @@ cab
         the code points of the characters only.
       </p>
 <a name="boost_regex.syntax.basic_extended.negation_"></a><h6>
-<a name="id792712"></a>
+<a name="id789970"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.negation_">Negation:</a>
       </h6>
 <p>
@@ -274,7 +274,7 @@ cab
         range <code class="computeroutput"><span class="identifier">a</span><span class="special">-</span><span class="identifier">c</span></code>.
       </p>
 <a name="boost_regex.syntax.basic_extended.character_classes_"></a><h6>
-<a name="id792766"></a>
+<a name="id790024"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.character_classes_">Character
         classes:</a>
       </h6>
@@ -284,7 +284,7 @@ cab
         <a class="link" href="character_classes.html" title="Character Class Names">character class names</a>.
       </p>
 <a name="boost_regex.syntax.basic_extended.collating_elements_"></a><h6>
-<a name="id792818"></a>
+<a name="id790075"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.collating_elements_">Collating
         Elements:</a>
       </h6>
@@ -312,7 +312,7 @@ cab
         matches a NUL character.
       </p>
 <a name="boost_regex.syntax.basic_extended.equivalence_classes_"></a><h6>
-<a name="id792920"></a>
+<a name="id790177"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.equivalence_classes_">Equivalence
         classes:</a>
       </h6>
@@ -329,7 +329,7 @@ cab
         or even all locales on one platform.
       </p>
 <a name="boost_regex.syntax.basic_extended.combinations_"></a><h6>
-<a name="id792977"></a>
+<a name="id790235"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.combinations_">Combinations:</a>
       </h6>
 <p>
@@ -337,7 +337,7 @@ cab
         <code class="computeroutput"><span class="special">[[:</span><span class="identifier">digit</span><span class="special">:]</span><span class="identifier">a</span><span class="special">-</span><span class="identifier">c</span><span class="special">[.</span><span class="identifier">NUL</span><span class="special">.]]</span></code>.
       </p>
 <a name="boost_regex.syntax.basic_extended.escapes"></a><h5>
-<a name="id793030"></a>
+<a name="id790288"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.escapes">Escapes</a>
       </h5>
 <p>
@@ -363,7 +363,7 @@ cab
         extensions are also supported by Boost.Regex:
       </p>
 <a name="boost_regex.syntax.basic_extended.escapes_matching_a_specific_character"></a><h6>
-<a name="id793073"></a>
+<a name="id790331"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.escapes_matching_a_specific_character">Escapes
         matching a specific character</a>
       </h6>
@@ -552,7 +552,7 @@ cab
 </tbody>
 </table></div>
 <a name="boost_regex.syntax.basic_extended._quot_single_character_quot__character_classes_"></a><h6>
-<a name="id793364"></a>
+<a name="id790963"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended._quot_single_character_quot__character_classes_">"Single
         character" character classes:</a>
       </h6>
@@ -706,7 +706,7 @@ cab
 </tbody>
 </table></div>
 <a name="boost_regex.syntax.basic_extended.character_properties"></a><h6>
-<a name="id793921"></a>
+<a name="id791451"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.character_properties">Character
         Properties</a>
       </h6>
@@ -813,7 +813,7 @@ cab
         matches any "digit" character, as does <code class="computeroutput"><span class="special">\</span><span class="identifier">p</span><span class="special">{</span><span class="identifier">digit</span><span class="special">}</span></code>.
       </p>
 <a name="boost_regex.syntax.basic_extended.word_boundaries"></a><h6>
-<a name="id794228"></a>
+<a name="id791759"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.word_boundaries">Word Boundaries</a>
       </h6>
 <p>
@@ -888,7 +888,7 @@ cab
 </tbody>
 </table></div>
 <a name="boost_regex.syntax.basic_extended.buffer_boundaries"></a><h6>
-<a name="id794384"></a>
+<a name="id791915"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.buffer_boundaries">Buffer
         boundaries</a>
       </h6>
@@ -979,7 +979,7 @@ cab
 </tbody>
 </table></div>
 <a name="boost_regex.syntax.basic_extended.continuation_escape"></a><h6>
-<a name="id794569"></a>
+<a name="id792099"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.continuation_escape">Continuation
         Escape</a>
       </h6>
@@ -991,7 +991,7 @@ cab
         match to start where the last one ended.
       </p>
 <a name="boost_regex.syntax.basic_extended.quoting_escape"></a><h6>
-<a name="id794597"></a>
+<a name="id792127"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.quoting_escape">Quoting
         escape</a>
       </h6>
@@ -1005,7 +1005,7 @@ cab
 <span class="special">\*+</span><span class="identifier">aaa</span>
 </pre>
 <a name="boost_regex.syntax.basic_extended.unicode_escapes"></a><h6>
-<a name="id794677"></a>
+<a name="id792207"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.unicode_escapes">Unicode
         escapes</a>
       </h6>
@@ -1056,7 +1056,7 @@ cab
 </tbody>
 </table></div>
 <a name="boost_regex.syntax.basic_extended.any_other_escape"></a><h6>
-<a name="id794779"></a>
+<a name="id792309"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.any_other_escape">Any other
         escape</a>
       </h6>
@@ -1065,7 +1065,7 @@ cab
         \@ matches a literal '@'.
       </p>
 <a name="boost_regex.syntax.basic_extended.operator_precedence"></a><h5>
-<a name="id794796"></a>
+<a name="id792326"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.operator_precedence">Operator
         precedence</a>
       </h5>
@@ -1101,7 +1101,7 @@ cab
 </li>
 </ol></div>
 <a name="boost_regex.syntax.basic_extended.what_gets_matched"></a><h5>
-<a name="id794929"></a>
+<a name="id792459"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.what_gets_matched">What
         Gets Matched</a>
       </h5>
@@ -1111,11 +1111,11 @@ cab
         rule</a>.
       </p>
 <a name="boost_regex.syntax.basic_extended.variations"></a><h4>
-<a name="id794951"></a>
+<a name="id792481"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.variations">Variations</a>
       </h4>
 <a name="boost_regex.syntax.basic_extended.egrep"></a><h5>
-<a name="id794964"></a>
+<a name="id792494"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.egrep">Egrep</a>
       </h5>
 <p>
@@ -1136,7 +1136,7 @@ cab
         used with the -E option.
       </p>
 <a name="boost_regex.syntax.basic_extended.awk"></a><h5>
-<a name="id795066"></a>
+<a name="id792596"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.awk">awk</a>
       </h5>
 <p>
@@ -1150,7 +1150,7 @@ cab
         these by default anyway.
       </p>
 <a name="boost_regex.syntax.basic_extended.options"></a><h4>
-<a name="id795091"></a>
+<a name="id792621"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.options">Options</a>
       </h4>
 <p>
@@ -1163,7 +1163,7 @@ cab
         modify how the case and locale sensitivity are to be applied.
       </p>
 <a name="boost_regex.syntax.basic_extended.references"></a><h4>
-<a name="id795169"></a>
+<a name="id792699"></a>
         <a class="link" href="basic_extended.html#boost_regex.syntax.basic_extended.references">References</a>
       </h4>
 <p>

doc/html/boost_regex/syntax/basic_syntax.html

@@ -28,7 +28,7 @@
       Expression Syntax</a>
 </h3></div></div></div>
 <a name="boost_regex.syntax.basic_syntax.synopsis"></a><h4>
-<a name="id795218"></a>
+<a name="id792749"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.synopsis">Synopsis</a>
       </h4>
 <p>
@@ -45,7 +45,7 @@
 <a name="boost_regex.posix_basic"></a><p>
       </p>
 <a name="boost_regex.syntax.basic_syntax.posix_basic_syntax"></a><h4>
-<a name="id795414"></a>
+<a name="id792944"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.posix_basic_syntax">POSIX
         Basic Syntax</a>
       </h4>
@@ -55,7 +55,7 @@
       </p>
 <pre class="programlisting">.[\*^$</pre>
 <a name="boost_regex.syntax.basic_syntax.wildcard_"></a><h5>
-<a name="id795435"></a>
+<a name="id792966"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.wildcard_">Wildcard:</a>
       </h5>
 <p>
@@ -73,7 +73,7 @@
         </li>
 </ul></div>
 <a name="boost_regex.syntax.basic_syntax.anchors_"></a><h5>
-<a name="id795480"></a>
+<a name="id793010"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.anchors_">Anchors:</a>
       </h5>
 <p>
@@ -85,7 +85,7 @@
         of an expression, or the last character of a sub-expression.
       </p>
 <a name="boost_regex.syntax.basic_syntax.marked_sub_expressions_"></a><h5>
-<a name="id795500"></a>
+<a name="id793031"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.marked_sub_expressions_">Marked
         sub-expressions:</a>
       </h5>
@@ -97,7 +97,7 @@
         by a back-reference.
       </p>
 <a name="boost_regex.syntax.basic_syntax.repeats_"></a><h5>
-<a name="id795531"></a>
+<a name="id793062"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.repeats_">Repeats:</a>
       </h5>
 <p>
@@ -155,7 +155,7 @@ aaaa
         to.
       </p>
 <a name="boost_regex.syntax.basic_syntax.back_references_"></a><h5>
-<a name="id795696"></a>
+<a name="id793982"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.back_references_">Back references:</a>
       </h5>
 <p>
@@ -173,7 +173,7 @@ aaaa
       </p>
 <pre class="programlisting">aaabba</pre>
 <a name="boost_regex.syntax.basic_syntax.character_sets_"></a><h5>
-<a name="id796514"></a>
+<a name="id794031"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.character_sets_">Character
         sets:</a>
       </h5>
@@ -186,7 +186,7 @@ aaaa
         A bracket expression may contain any combination of the following:
       </p>
 <a name="boost_regex.syntax.basic_syntax.single_characters_"></a><h6>
-<a name="id796534"></a>
+<a name="id794051"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.single_characters_">Single
         characters:</a>
       </h6>
@@ -195,7 +195,7 @@ aaaa
         or 'c'.
       </p>
 <a name="boost_regex.syntax.basic_syntax.character_ranges_"></a><h6>
-<a name="id796565"></a>
+<a name="id794082"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.character_ranges_">Character
         ranges:</a>
       </h6>
@@ -211,7 +211,7 @@ aaaa
         of the characters only.
       </p>
 <a name="boost_regex.syntax.basic_syntax.negation_"></a><h6>
-<a name="id796622"></a>
+<a name="id794139"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.negation_">Negation:</a>
       </h6>
 <p>
@@ -220,7 +220,7 @@ aaaa
         range a-c.
       </p>
 <a name="boost_regex.syntax.basic_syntax.character_classes_"></a><h6>
-<a name="id796660"></a>
+<a name="id794177"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.character_classes_">Character
         classes:</a>
       </h6>
@@ -230,7 +230,7 @@ aaaa
         <a class="link" href="character_classes.html" title="Character Class Names">character class names</a>.
       </p>
 <a name="boost_regex.syntax.basic_syntax.collating_elements_"></a><h6>
-<a name="id796712"></a>
+<a name="id794229"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.collating_elements_">Collating
         Elements:</a>
       </h6>
@@ -259,7 +259,7 @@ aaaa
         element names</a>.
       </p>
 <a name="boost_regex.syntax.basic_syntax.equivalence_classes_"></a><h6>
-<a name="id796803"></a>
+<a name="id794320"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.equivalence_classes_">Equivalence
         classes:</a>
       </h6>
@@ -276,7 +276,7 @@ aaaa
         or even all locales on one platform.
       </p>
 <a name="boost_regex.syntax.basic_syntax.combinations_"></a><h6>
-<a name="id796860"></a>
+<a name="id794378"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.combinations_">Combinations:</a>
       </h6>
 <p>
@@ -284,7 +284,7 @@ aaaa
         <code class="computeroutput"><span class="special">[[:</span><span class="identifier">digit</span><span class="special">:]</span><span class="identifier">a</span><span class="special">-</span><span class="identifier">c</span><span class="special">[.</span><span class="identifier">NUL</span><span class="special">.]].</span></code>
       </p>
 <a name="boost_regex.syntax.basic_syntax.escapes"></a><h5>
-<a name="id796913"></a>
+<a name="id794430"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.escapes">Escapes</a>
       </h5>
 <p>
@@ -299,7 +299,7 @@ aaaa
         will match either a literal '\' or a '^'.
       </p>
 <a name="boost_regex.syntax.basic_syntax.what_gets_matched"></a><h4>
-<a name="id796947"></a>
+<a name="id794464"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.what_gets_matched">What Gets
         Matched</a>
       </h4>
@@ -309,13 +309,13 @@ aaaa
         rule</a>.
       </p>
 <a name="boost_regex.syntax.basic_syntax.variations"></a><h4>
-<a name="id796968"></a>
+<a name="id794486"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.variations">Variations</a>
       </h4>
 <a name="boost_regex.grep_syntax"></a><p>
       </p>
 <a name="boost_regex.syntax.basic_syntax.grep"></a><h5>
-<a name="id796989"></a>
+<a name="id794506"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.grep">Grep</a>
       </h5>
 <p>
@@ -333,7 +333,7 @@ aaaa
         As its name suggests, this behavior is consistent with the Unix utility grep.
       </p>
 <a name="boost_regex.syntax.basic_syntax.emacs"></a><h5>
-<a name="id797084"></a>
+<a name="id794601"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.emacs">emacs</a>
       </h5>
 <p>
@@ -613,7 +613,7 @@ aaaa
         leftmost-longest rule</a>.
       </p>
 <a name="boost_regex.syntax.basic_syntax.options"></a><h4>
-<a name="id797501"></a>
+<a name="id795018"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.options">Options</a>
       </h4>
 <p>
@@ -627,7 +627,7 @@ aaaa
         options</a> modify how the case and locale sensitivity are to be applied.
       </p>
 <a name="boost_regex.syntax.basic_syntax.references"></a><h4>
-<a name="id797608"></a>
+<a name="id795125"></a>
         <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.references">References</a>
       </h4>
 <p>

doc/html/boost_regex/syntax/perl_syntax.html

@@ -28,7 +28,7 @@
       Syntax</a>
 </h3></div></div></div>
 <a name="boost_regex.syntax.perl_syntax.synopsis"></a><h4>
-<a name="id786230"></a>
+<a name="id783363"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.synopsis">Synopsis</a>
       </h4>
 <p>
@@ -43,7 +43,7 @@
 </span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span> <span class="identifier">e2</span><span class="special">(</span><span class="identifier">my_expression</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span><span class="special">::</span><span class="identifier">perl</span><span class="special">|</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span><span class="special">::</span><span class="identifier">icase</span><span class="special">);</span>
 </pre>
 <a name="boost_regex.syntax.perl_syntax.perl_regular_expression_syntax"></a><h4>
-<a name="id786378"></a>
+<a name="id783510"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.perl_regular_expression_syntax">Perl
         Regular Expression Syntax</a>
       </h4>
@@ -53,7 +53,7 @@
       </p>
 <pre class="programlisting">.[{()\*+?|^$</pre>
 <a name="boost_regex.syntax.perl_syntax.wildcard"></a><h5>
-<a name="id786402"></a>
+<a name="id783534"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.wildcard">Wildcard</a>
       </h5>
 <p>
@@ -73,7 +73,7 @@
         </li>
 </ul></div>
 <a name="boost_regex.syntax.perl_syntax.anchors"></a><h5>
-<a name="id786448"></a>
+<a name="id783581"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.anchors">Anchors</a>
       </h5>
 <p>
@@ -83,7 +83,7 @@
         A '$' character shall match the end of a line.
       </p>
 <a name="boost_regex.syntax.perl_syntax.marked_sub_expressions"></a><h5>
-<a name="id786470"></a>
+<a name="id783603"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.marked_sub_expressions">Marked
         sub-expressions</a>
       </h5>
@@ -94,7 +94,7 @@
         can also repeated, or referred to by a back-reference.
       </p>
 <a name="boost_regex.syntax.perl_syntax.non_marking_grouping"></a><h5>
-<a name="id786496"></a>
+<a name="id783629"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.non_marking_grouping">Non-marking
         grouping</a>
       </h5>
@@ -107,7 +107,7 @@
         without splitting out any separate sub-expressions.
       </p>
 <a name="boost_regex.syntax.perl_syntax.repeats"></a><h5>
-<a name="id786532"></a>
+<a name="id783665"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.repeats">Repeats</a>
       </h5>
 <p>
@@ -188,7 +188,7 @@
         to be applied to.
       </p>
 <a name="boost_regex.syntax.perl_syntax.non_greedy_repeats"></a><h5>
-<a name="id786769"></a>
+<a name="id783901"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.non_greedy_repeats">Non greedy
         repeats</a>
       </h5>
@@ -218,7 +218,7 @@
         while consuming as little input as possible.
       </p>
 <a name="boost_regex.syntax.perl_syntax.pocessive_repeats"></a><h5>
-<a name="id786828"></a>
+<a name="id783960"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.pocessive_repeats">Pocessive
         repeats</a>
       </h5>
@@ -250,7 +250,7 @@
         while giving nothing back.
       </p>
 <a name="boost_regex.syntax.perl_syntax.back_references"></a><h5>
-<a name="id786886"></a>
+<a name="id784019"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.back_references">Back references</a>
       </h5>
 <p>
@@ -340,10 +340,27 @@
               </p>
               </td>
 </tr>
+<tr>
+<td>
+              <p>
+                <code class="literal">\g{one}</code>
+              </p>
+              </td>
+<td>
+              <p>
+                Match whatever matched the sub-expression named "one"
+              </p>
+              </td>
+</tr>
 </tbody>
 </table></div>
+<p>
+        Finally the \k escape can be used to refer to named subexpressions, for example
+        <code class="literal">\k&lt;two&gt;</code> will match whatever matched the subexpression
+        named "two".
+      </p>
 <a name="boost_regex.syntax.perl_syntax.alternation"></a><h5>
-<a name="id787076"></a>
+<a name="id784239"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.alternation">Alternation</a>
       </h5>
 <p>
@@ -370,7 +387,7 @@
         <code class="literal">(?:abc)??</code> has exactly the same effect.
       </p>
 <a name="boost_regex.syntax.perl_syntax.character_sets"></a><h5>
-<a name="id787144"></a>
+<a name="id784307"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.character_sets">Character sets</a>
       </h5>
 <p>
@@ -382,7 +399,7 @@
         A bracket expression may contain any combination of the following:
       </p>
 <a name="boost_regex.syntax.perl_syntax.single_characters"></a><h6>
-<a name="id787176"></a>
+<a name="id784612"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.single_characters">Single characters</a>
       </h6>
 <p>
@@ -390,7 +407,7 @@
         'b', or 'c'.
       </p>
 <a name="boost_regex.syntax.perl_syntax.character_ranges"></a><h6>
-<a name="id787607"></a>
+<a name="id784633"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.character_ranges">Character
         ranges</a>
       </h6>
@@ -404,7 +421,7 @@
         sensitive.
       </p>
 <a name="boost_regex.syntax.perl_syntax.negation"></a><h6>
-<a name="id787640"></a>
+<a name="id784666"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.negation">Negation</a>
       </h6>
 <p>
@@ -413,7 +430,7 @@
         matches any character that is not in the range <code class="literal">a-c</code>.
       </p>
 <a name="boost_regex.syntax.perl_syntax.character_classes"></a><h6>
-<a name="id787667"></a>
+<a name="id784693"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.character_classes">Character
         classes</a>
       </h6>
@@ -424,7 +441,7 @@
         class names</a>.
       </p>
 <a name="boost_regex.syntax.perl_syntax.collating_elements"></a><h6>
-<a name="id787700"></a>
+<a name="id784726"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.collating_elements">Collating
         Elements</a>
       </h6>
@@ -446,7 +463,7 @@
         matches a <code class="literal">\0</code> character.
       </p>
 <a name="boost_regex.syntax.perl_syntax.equivalence_classes"></a><h6>
-<a name="id787762"></a>
+<a name="id784788"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.equivalence_classes">Equivalence
         classes</a>
       </h6>
@@ -463,7 +480,7 @@
         or even all locales on one platform.
       </p>
 <a name="boost_regex.syntax.perl_syntax.escaped_characters"></a><h6>
-<a name="id787810"></a>
+<a name="id784836"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.escaped_characters">Escaped
         Characters</a>
       </h6>
@@ -475,7 +492,7 @@
         is <span class="emphasis"><em>not</em></span> a "word" character.
       </p>
 <a name="boost_regex.syntax.perl_syntax.combinations"></a><h6>
-<a name="id787879"></a>
+<a name="id784905"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.combinations">Combinations</a>
       </h6>
 <p>
@@ -483,7 +500,7 @@
         <code class="literal">[[:digit:]a-c[.NUL.]]</code>.
       </p>
 <a name="boost_regex.syntax.perl_syntax.escapes"></a><h5>
-<a name="id787900"></a>
+<a name="id784926"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.escapes">Escapes</a>
       </h5>
 <p>
@@ -675,7 +692,7 @@
 </tbody>
 </table></div>
 <a name="boost_regex.syntax.perl_syntax._quot_single_character_quot__character_classes_"></a><h6>
-<a name="id788288"></a>
+<a name="id785314"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax._quot_single_character_quot__character_classes_">"Single
         character" character classes:</a>
       </h6>
@@ -877,7 +894,7 @@
 </tbody>
 </table></div>
 <a name="boost_regex.syntax.perl_syntax.character_properties"></a><h6>
-<a name="id788888"></a>
+<a name="id785914"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.character_properties">Character
         Properties</a>
       </h6>
@@ -985,7 +1002,7 @@
         as does <code class="literal">\p{digit}</code>.
       </p>
 <a name="boost_regex.syntax.perl_syntax.word_boundaries"></a><h6>
-<a name="id789177"></a>
+<a name="id786203"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.word_boundaries">Word Boundaries</a>
       </h6>
 <p>
@@ -1004,7 +1021,7 @@
         <code class="literal">\B</code> Matches only when not at a word boundary.
       </p>
 <a name="boost_regex.syntax.perl_syntax.buffer_boundaries"></a><h6>
-<a name="id789229"></a>
+<a name="id786255"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.buffer_boundaries">Buffer boundaries</a>
       </h6>
 <p>
@@ -1029,7 +1046,7 @@
         to the regular expression <code class="literal">\n*\z</code>
       </p>
 <a name="boost_regex.syntax.perl_syntax.continuation_escape"></a><h6>
-<a name="id789269"></a>
+<a name="id786295"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.continuation_escape">Continuation
         Escape</a>
       </h6>
@@ -1041,7 +1058,7 @@
         one ended.
       </p>
 <a name="boost_regex.syntax.perl_syntax.quoting_escape"></a><h6>
-<a name="id789291"></a>
+<a name="id786317"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.quoting_escape">Quoting escape</a>
       </h6>
 <p>
@@ -1054,7 +1071,7 @@
 <span class="special">\*+</span><span class="identifier">aaa</span>
 </pre>
 <a name="boost_regex.syntax.perl_syntax.unicode_escapes"></a><h6>
-<a name="id789338"></a>
+<a name="id786364"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.unicode_escapes">Unicode escapes</a>
       </h6>
 <p>
@@ -1064,7 +1081,7 @@
         followed by a sequence of zero or more combining characters.
       </p>
 <a name="boost_regex.syntax.perl_syntax.matching_line_endings"></a><h6>
-<a name="id789364"></a>
+<a name="id786390"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.matching_line_endings">Matching
         Line Endings</a>
       </h6>
@@ -1073,7 +1090,7 @@
         sequence, specifically it is identical to the expression <code class="literal">(?&gt;\x0D\x0A?|[\x0A-\x0C\x85\x{2028}\x{2029}])</code>.
       </p>
 <a name="boost_regex.syntax.perl_syntax.keeping_back_some_text"></a><h6>
-<a name="id789391"></a>
+<a name="id786417"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.keeping_back_some_text">Keeping
         back some text</a>
       </h6>
@@ -1088,7 +1105,7 @@
         This can be used to simulate variable width lookbehind assertions.
       </p>
 <a name="boost_regex.syntax.perl_syntax.any_other_escape"></a><h6>
-<a name="id789421"></a>
+<a name="id786447"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.any_other_escape">Any other
         escape</a>
       </h6>
@@ -1097,7 +1114,7 @@
         \@ matches a literal '@'.
       </p>
 <a name="boost_regex.syntax.perl_syntax.perl_extended_patterns"></a><h5>
-<a name="id789437"></a>
+<a name="id786463"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.perl_extended_patterns">Perl
         Extended Patterns</a>
       </h5>
@@ -1105,15 +1122,37 @@
         Perl-specific extensions to the regular expression syntax all start with
         <code class="literal">(?</code>.
       </p>
+<a name="boost_regex.syntax.perl_syntax.named_subexpressions"></a><h6>
+<a name="id786485"></a>
+        <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.named_subexpressions">Named
+        Subexpressions</a>
+      </h6>
+<p>
+        You can create a named subexpression using:
+      </p>
+<pre class="programlisting"><span class="special">(?&lt;</span><span class="identifier">NAME</span><span class="special">&gt;</span><span class="identifier">expression</span><span class="special">)</span>
+</pre>
+<p>
+        Which can be then be refered to by the name <span class="emphasis"><em>NAME</em></span>. Alternatively
+        you can delimit the name using 'NAME' as in:
+      </p>
+<pre class="programlisting"><span class="special">(?</span><span class="char">'NAME'</span><span class="identifier">expression</span><span class="special">)</span>
+</pre>
+<p>
+        These named subexpressions can be refered to in a backreference using either
+        <code class="literal">\g{NAME}</code> or <code class="literal">\k&lt;NAME&gt;</code> and can
+        also be refered to by name in a <a class="link" href="../format/perl_format.html" title="Perl Format String Syntax">Perl</a>
+        format string for search and replace operations, or in the <a class="link" href="../ref/match_results.html" title="match_results"><code class="computeroutput"><span class="identifier">match_results</span></code></a> member functions.
+      </p>
 <a name="boost_regex.syntax.perl_syntax.comments"></a><h6>
-<a name="id789459"></a>
+<a name="id786580"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.comments">Comments</a>
       </h6>
 <p>
         <code class="literal">(?# ... )</code> is treated as a comment, it's contents are ignored.
       </p>
 <a name="boost_regex.syntax.perl_syntax.modifiers"></a><h6>
-<a name="id789482"></a>
+<a name="id786603"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.modifiers">Modifiers</a>
       </h6>
 <p>
@@ -1127,7 +1166,7 @@
         pattern only.
       </p>
 <a name="boost_regex.syntax.perl_syntax.non_marking_groups"></a><h6>
-<a name="id789517"></a>
+<a name="id786637"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.non_marking_groups">Non-marking
         groups</a>
       </h6>
@@ -1136,7 +1175,7 @@
         an additional sub-expression.
       </p>
 <a name="boost_regex.syntax.perl_syntax.lookahead"></a><h6>
-<a name="id789538"></a>
+<a name="id786659"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.lookahead">Lookahead</a>
       </h6>
 <p>
@@ -1159,7 +1198,7 @@
         could be used to validate the password.
       </p>
 <a name="boost_regex.syntax.perl_syntax.lookbehind"></a><h6>
-<a name="id789613"></a>
+<a name="id786733"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.lookbehind">Lookbehind</a>
       </h6>
 <p>
@@ -1173,7 +1212,7 @@
         (pattern must be of fixed length).
       </p>
 <a name="boost_regex.syntax.perl_syntax.independent_sub_expressions"></a><h6>
-<a name="id789645"></a>
+<a name="id786766"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.independent_sub_expressions">Independent
         sub-expressions</a>
       </h6>
@@ -1186,7 +1225,7 @@
         no match is found at all.
       </p>
 <a name="boost_regex.syntax.perl_syntax.conditional_expressions"></a><h6>
-<a name="id789676"></a>
+<a name="id788436"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.conditional_expressions">Conditional
         Expressions</a>
       </h6>
@@ -1205,7 +1244,7 @@
         sub-expression has been matched).
       </p>
 <a name="boost_regex.syntax.perl_syntax.operator_precedence"></a><h5>
-<a name="id789731"></a>
+<a name="id788491"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.operator_precedence">Operator
         precedence</a>
       </h5>
@@ -1240,7 +1279,7 @@
         </li>
 </ol></div>
 <a name="boost_regex.syntax.perl_syntax.what_gets_matched"></a><h4>
-<a name="id791324"></a>
+<a name="id788581"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.what_gets_matched">What gets
         matched</a>
       </h4>
@@ -1415,7 +1454,7 @@
 </tbody>
 </table></div>
 <a name="boost_regex.syntax.perl_syntax.variations"></a><h4>
-<a name="id791681"></a>
+<a name="id788939"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.variations">Variations</a>
       </h4>
 <p>
@@ -1424,7 +1463,7 @@
         and <code class="literal">JScript</code></a> are all synonyms for <code class="literal">perl</code>.
       </p>
 <a name="boost_regex.syntax.perl_syntax.options"></a><h4>
-<a name="id791728"></a>
+<a name="id788986"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.options">Options</a>
       </h4>
 <p>
@@ -1436,7 +1475,7 @@
         are to be applied.
       </p>
 <a name="boost_regex.syntax.perl_syntax.pattern_modifiers"></a><h4>
-<a name="id791776"></a>
+<a name="id789034"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.pattern_modifiers">Pattern
         Modifiers</a>
       </h4>
@@ -1448,7 +1487,7 @@
         and <code class="literal">no_mod_s</code></a>.
       </p>
 <a name="boost_regex.syntax.perl_syntax.references"></a><h4>
-<a name="id791829"></a>
+<a name="id789086"></a>
         <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.references">References</a>
       </h4>
 <p>