https://svn.boost.org/trac10/ticket/1081 <p> "" is a valid Perl-style regular expression. It means "match anything". boost::regex throws an exception when this is compiled. </p> <p> How difficult would it be to allow the empty string? </p> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/1081 Trac 1.4.3 John Maddock Tue, 23 Dec 2008 19:06:08 GMT https://svn.boost.org/trac10/ticket/1081#comment:1 https://svn.boost.org/trac10/ticket/1081#comment:1 <ul> <li><strong>status</strong> <span class="trac-field-old">new</span> → <span class="trac-field-new">closed</span> </li> <li><strong>resolution</strong> → <span class="trac-field-new">fixed</span> </li> </ul> <p> (In <a class="changeset" href="https://svn.boost.org/trac10/changeset/50374" title="Empty expressions, and empty alternatives are now allowed when using ...">[50374]</a>) Empty expressions, and empty alternatives are now allowed when using the Perl regular expression syntax. This change has been added for Perl compatibility, when the new [syntax_option_type] ['no_empty_expressions] is set then the old behaviour is preserved and empty expressions are prohibited. This is issue [@<a class="ext-link" href="https://svn.boost.org/trac/boost/ticket/1081"><span class="icon">​</span>https://svn.boost.org/trac/boost/ticket/1081</a> <a class="closed ticket" href="https://svn.boost.org/trac10/ticket/1081" title="#1081: Bugs: Empty string rejected as perl-style regex (closed: fixed)">#1081</a>]. </p> <p> Fixes <a class="closed ticket" href="https://svn.boost.org/trac10/ticket/1081" title="#1081: Bugs: Empty string rejected as perl-style regex (closed: fixed)">#1081</a>. </p> Ticket