"fusion/functional.html">Functional</a></span></dt>
<dd><dl>
<dt><span class="section"><a href="fusion/functional/concepts.html">Concepts</a></span></dt>
<dd><dl>
<dt><span class="section"><a href="fusion/functional/concepts/callable.html">Callable Object</a></span></dt>
<dt><span class="section"><a href="fusion/functional/concepts/reg_callable.html">Regular Callable
        Object</a></span></dt>
<dt><span class="section"><a href="fusion/functional/concepts/def_callable.html">Deferred Callable
        Obje