span class="type-var">'a</span> <a href="index.html#type-t">t</a></span> * <span><span class="type-var">'b</span> <a href="index.html#type-t">t</a></span></code></dt><dd><p>This function behaves as <code>partition</code> then a <code>map</code>. First we do a <code>partition</code> with the function assuming <code>Some</code> means <code>true</code>, then for all the extracted elements we map <code>f</code> on them and return the results.</p><p>Formally: <code>partition_map f l = (filter (fun a -&gt; f a = 