</h1></div></div></div>
<ol class="children children-li"><li>
	<a href="../reference/policies/base.html" ><code>base</code></a>
<p>Base class of most policy classes defining the narrow observer policies.</p><ol><li>
	<a href="../reference/policies/base/ub.html" ><code>static void _ub(Impl &amp;&amp;)</code></a>
<p>Special function which causes noticeable hard undefined behaviour.</p><li>
	<a href="../reference/policies/base/has_value.html" ><code>static bool _has_value(Impl &amp;&amp;) noexcept</code></a>
<