mputeroutput"><span class="identifier">element_type</span><span class="special">;</span></code></span></dt>
<dd><p>
                <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">element_type</span></code> if such a type exists;
                otherwise <code class="computeroutput"><span class="identifier">U</span></code> if <code class="computeroutput"><span class="identifier">T</span></code> is a class template instantiation
         