class="identifier">T</span></code> is default
        constructible, while:
      </p>
<pre class="programlisting"><span class="identifier">is_constructible</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&amp;&gt;::</span><span class="identifier">value</span>
</pre>
<p>
        Indicates whether <code class="computeroutput"><span class="identifier">T</span></code>