pecial">[</span><span class="special">&amp;</span><span class="special">]</span> <span class="special">{</span> <span class="comment">// Optional.</span>
                <span class="identifier">BOOST_CONTRACT_ASSERT</span><span class="special">(</span><span class="special">...</span><span class="special">)</span><span class="special">;</span>
                <span class="special">...</span>
            <span class="special">}</span><span class="special">)</span>
        <span class="special">;</span>

    