class="type-var">'a</span> <a href="index.html#type-t">t</a></span> <span>&#45;&gt;</span> <span class="type-var">'m</span></code></dt><dd><p><code>fold_map ~m ~f t</code> is a map of the elements of <code>t</code> in the monoid <code>m</code> combines with <code>m.op</code>.</p><p>E.g.,</p><pre><code class="ml"># Foldable.List.fold_map ~m:(module Monoid.Int.Sum) ~f:int_of_string [&quot;1&quot;;&quot;2&quot;;&quot;3&quot;;&quot;4&quot;];;
- : int = 10</code></pre></dd></dl><dl><dt class="spec value" id="val