https://svn.boost.org/trac10/ticket/6017 <p> % diff boost/math/special_functions/detail/bessel_jy.hpp boost/math/special_functions/detail/bessel_jy_.hpp 19a20 </p> <blockquote class="citation"> <p> #include &lt;boost/math/special_functions/detail/bessel_jy_series.hpp&gt; </p> </blockquote> <p> GCC seems fine with/without the include. Here is the clang error without the include: </p> <p> boost/boost/math/special_functions/detail/bessel_jy.hpp:363:16: error: </p> <blockquote> <p> call to function 'bessel_yn_small_z' that is neither visible in the template definition nor found by argument-dependent lookup </p> <blockquote> <p> Yv = bessel_yn_small_z(n, x, &amp;Yv_scale, pol); </p> <blockquote> <p> </p> </blockquote> </blockquote> </blockquote> <p> boost/boost/math/special_functions/detail/bessel_jy_series.hpp:213:3: note: </p> <blockquote> <p> 'bessel_yn_small_z' should be declared prior to the call site or in namespace 'boost::math::policies' </p> </blockquote> <p> T bessel_yn_small_z(int n, T z, T* scale, const Policy&amp; pol) </p> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/6017 Trac 1.4.3 John Maddock Thu, 13 Oct 2011 17:31:02 GMT https://svn.boost.org/trac10/ticket/6017#comment:1 https://svn.boost.org/trac10/ticket/6017#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/74937" title="Add missing #include. Fixes #6017.">[74937]</a>) Add missing #include. Fixes <a class="closed ticket" href="https://svn.boost.org/trac10/ticket/6017" title="#6017: Patches: missing include (clang compatibility) (closed: fixed)">#6017</a>. </p> Ticket