https://svn.boost.org/trac10/ticket/4172 <p> in bind/placeholders.hpp there is a workaround for compiled headers sharing anonymous name space information causing multiply defined errors with placeholders </p> <p> see <a class="ext-link" href="http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29085"><span class="icon">​</span>http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29085</a> </p> <p> Unfortunately the ifdef for activating the workaround in boost/bind/placeholders.hpp is incorrect as the bug was fixed in gcc 4.2 and still exists in gcc 4.1 </p> <p> The check </p> <blockquote> <p> defined(<span class="underline">GNUC</span>) &amp;&amp; (<span class="underline">GNUC</span> * 100 + <span class="underline">GNUC_MINOR</span> == 400) </p> </blockquote> <p> should be replaced with </p> <blockquote> <p> defined(<span class="underline">GNUC</span>) &amp;&amp; (<span class="underline">GNUC</span> * 100 + <span class="underline">GNUC_MINOR</span> &lt; 420) </p> </blockquote> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/4172 Trac 1.4.3 Peter Dimov Wed, 26 May 2010 19:34:16 GMT https://svn.boost.org/trac10/ticket/4172#comment:2 https://svn.boost.org/trac10/ticket/4172#comment:2 <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/63828" title="Merge [62251] to release. Fixes #4172.">[63828]</a>) Merge <a class="changeset" href="https://svn.boost.org/trac10/changeset/62251" title="Fix version check, as g++ 4.1 still has the PCH bug. Refs #4172.">[62251]</a> to release. Fixes <a class="closed ticket" href="https://svn.boost.org/trac10/ticket/4172" title="#4172: Bugs: bind/placeholders.hpp workaround for multiply defined anon namespace ... (closed: fixed)">#4172</a>. </p> Ticket