ass="keyword">this</span><span class="special">,</span> <span class="identifier">value</span><span class="special">)</span>
            <span class="special">.</span><span class="identifier">precondition</span><span class="special">([&amp;]</span> <span class="special">{</span> <span class="comment">// Checked in OR with base preconditions.</span>
                <span class="identifier">BOOST_CONTRACT_ASSERT</span><span class="special">(</span><span class="identifier">size</span><span class="special">()</s