ier">detail</span>
      <span class="special">{</span>
        <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">struct</span> <span class="identifier">constant_pi</span>
        <span class="special">{</span>
          <span class="keyword">private</span><span class="special">:</span>
            <span class="comment">// Default implementations from string of dec