">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">elliptic_root_functor_1deriv</span>
<span class="special">{</span> <span class="comment">// Functor also returning 1st derviative.</span>
   <span class="identifier">BOOST_STATIC_ASSERT_MSG</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">is_integral</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;::</span