https://svn.boost.org/trac10/ticket/5698 <p> I tested this </p> <pre class="wiki"> template&lt;typename Args, typename Tag&gt; struct contains_parameter : mpl::not_&lt; typename boost::is_void&lt; typename parameter::binding&lt; Args, Tag, void &gt;::type &gt;::type &gt; {}; </pre><p> which first appeared here: </p> <p> <a class="ext-link" href="http://boost.2283326.n4.nabble.com/boost-users-Boost-Parameter-ArgumentPack-is-type-contained-td3415943.html"><span class="icon">​</span>http://boost.2283326.n4.nabble.com/boost-users-Boost-Parameter-ArgumentPack-is-type-contained-td3415943.html</a> </p> <p> and would like to suggest it as an addition. </p> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/5698 Trac 1.4.3