 <span>&#45;&gt;</span> <a href="index.html#type-make_t">make_t</a></code></dt><dt class="spec value" id="val-exists_str"><a href="#val-exists_str" class="anchor"></a><code><span class="keyword">val</span> exists_str : <span>f:<span>(string <span>&#45;&gt;</span> bool)</span></span> <span>&#45;&gt;</span> <a href="index.html#type-t">t</a> <span>&#45;&gt;</span> bool</code></dt><dt class="spec value" id="val-of_foreign_id"><a href="#val-of_foreign_id" class="anchor"></a><code><span class="keyword">val</span>