https://svn.boost.org/trac10/ticket/3413 <p> Below is a thread which describes exactly the same error I've encountered in Boost 1.40. There also is a patch to fix this issue </p> <p> <a class="ext-link" href="http://www.nabble.com/-Spirit2--Error-with-forward-declaration-of-stdext::hash_map.-td21818384.html"><span class="icon">​</span>http://www.nabble.com/-Spirit2--Error-with-forward-declaration-of-stdext::hash_map.-td21818384.html</a> </p> <p> The correct code should be for is_std_hash_map.hpp: </p> <p> namespace boost { </p> <blockquote> <p> template&lt;class T&gt; struct is_std_hash_map </p> <blockquote> <p> : boost::mpl::false_ </p> </blockquote> <p> {}; </p> </blockquote> <blockquote> <p> template&lt; </p> <blockquote> <p> class Kty </p> </blockquote> <p> , class Ty , class Tr , class Alloc </p> <blockquote class="citation"> </blockquote> </blockquote> <blockquote> <p> struct is_std_hash_map&lt; ::stdext::hash_map&lt;Kty,Ty,Tr,Alloc&gt; &gt; </p> <blockquote> <p> : boost::mpl::true_ </p> </blockquote> <p> {}; </p> </blockquote> <blockquote> <p> template&lt;class T&gt; struct is_std_hash_multimap </p> <blockquote> <p> : boost::mpl::false_ </p> </blockquote> <p> {}; </p> </blockquote> <blockquote> <p> template&lt; </p> <blockquote> <p> class Kty </p> </blockquote> <p> , class Ty , class Tr , class Alloc </p> <blockquote class="citation"> </blockquote> </blockquote> <blockquote> <p> struct is_std_hash_multimap&lt; ::stdext::hash_multimap&lt;Kty,Ty,Tr,Alloc&gt; &gt; </p> <blockquote> <p> : boost::mpl::true_ </p> </blockquote> <p> {}; </p> </blockquote> <p> } </p> <p> The correct code for std_hash_map_fwd.hpp: </p> <p> namespace stdext { </p> <blockquote> <p> template&lt; </p> <blockquote> <p> class Kty </p> </blockquote> <p> , class Ty , class Tr , class Alloc </p> <blockquote class="citation"> </blockquote> </blockquote> <blockquote> <p> class hash_map; </p> </blockquote> <blockquote> <p> template&lt; </p> <blockquote> <p> class Kty </p> </blockquote> <p> , class Ty , class Tr , class Alloc </p> <blockquote class="citation"> </blockquote> </blockquote> <blockquote> <p> class hash_multimap; </p> </blockquote> <p> } </p> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/3413 Trac 1.4.3 Steven Watanabe Mon, 07 Sep 2009 14:25:50 GMT https://svn.boost.org/trac10/ticket/3413#comment:1 https://svn.boost.org/trac10/ticket/3413#comment:1 <ul> <li><strong>owner</strong> set to <span class="trac-author">Joel de Guzman</span> </li> <li><strong>component</strong> <span class="trac-field-old">None</span> → <span class="trac-field-new">spirit</span> </li> </ul> <p> I thought that I had fixed this in the trunk. Looks like it was never merged. </p> Ticket Steven Watanabe Thu, 17 Sep 2009 15:26:04 GMT https://svn.boost.org/trac10/ticket/3413#comment:2 https://svn.boost.org/trac10/ticket/3413#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> Ticket