an class="special">&amp;);</span>
<span class="keyword">struct</span> <span class="identifier">B</span> <span class="special">{</span> <span class="keyword">operator</span> <span class="identifier">A</span><span class="special">();</span> <span class="special">};</span>
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">has_modulus_assign</span><span class="special">&lt;</span><span class="identifier">A</span><span class="special">&gt;::</span><span class="identifie