fier">parenthesized_type</span><span class="special">&gt;::</span><span class="identifier">arg1_type</span>
</pre><p>
      Essentially, the type is wrapped between round parenthesis <code class="computeroutput"><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">map</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">,</span>
      <span class="keyword">char</span><span class="special">&gt;)</span>