ode class="computeroutput"><span class="identifier">Ti</span></code>
          is default-constructible.
        </p>
<p>
          <span class="bold"><strong>Semantics</strong></span>: Default initializes each element
          of the tuple.
        </p>
<pre class="programlisting"><span class="identifier">tuple</span><span class="special">(</span><span class="identifier">P1</span><span class="special">,</span><span class="identifier">P2</span><span class="special">,...,</span><span class="identifier">PN</