a <a href="../../reference/types/success_type.html" class="api-reference"><code>success_type&lt;T&gt;</code></a>.</li>
<li>Is not a <a href="../../reference/types/failure_type.html" class="api-reference"><code>failure_type&lt;EC, EP = void&gt;</code></a>.</li>
<li>Is not an array.</li>
<li>Is either <code>void</code>, or else is an <code>Object</code> and is <code>Destructible</code>.</li>
</ul>

<p><em>Namespace</em>: <code>BOOST_OUTCOME_V2_NAMESPACE::trait</code></p>

<p><em>Header</em>: <code>&lt;boost/o