</span>.
      </p>
<p>
        The return type of these functions is computed using the __arg_pomotion_rules
        when the arguments are of different types: when they are the same type then
        the result is the same type as the arguments.
      </p>
<pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T1</span><span class="special">,</span> <span class="keyword">class</span> <span class="identi