https://svn.boost.org/trac10/ticket/12130 <p> In "icu.hpp", the utf8 and utf16 implementations of do_regex_match() use the copy_results() function which barely assigns "first" and "second" members for each "sub_match". But when BOOST_REGEX_MATCH_EXTRA is defined, sub_match'es contain alos "m_captures" whose content does not get copied inside copy_results(). This leads to empty captures() for all sub_match'es. </p> <p> the utf32 version uses "match_results" directly, so the problem does not take place. </p> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/12130 Trac 1.4.3 John Maddock Sun, 12 Jun 2016 12:10:21 GMT https://svn.boost.org/trac10/ticket/12130#comment:1 https://svn.boost.org/trac10/ticket/12130#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> <li><strong>milestone</strong> <span class="trac-field-old">To Be Determined</span> → <span class="trac-field-new">Boost 1.62.0</span> </li> </ul> <p> Fixed in <a class="ext-link" href="https://github.com/boostorg/regex/commit/a824b7d236e1084e06a3835d02cacc35772462d1"><span class="icon">​</span>https://github.com/boostorg/regex/commit/a824b7d236e1084e06a3835d02cacc35772462d1</a> </p> <p> Thanks for the report! </p> Ticket