al-join" class="anchor"></a><code><span class="keyword">val</span> join : <a href="index.html#type-t">t</a> <span>&#45;&gt;</span> <a href="index.html#type-t">t</a> <span>&#45;&gt;</span> <a href="index.html#type-t">t</a></code></dt><dd><p>Unique upper bound over two types: the most precise type that is a supertype of both. Practically, joins occur e.g. when two branches of execution flow are getting merged.</p></dd></dl><dl><dt class="spec value" id="val-is_considered_nonnull"><a href="#val-is_considered_n