declaring other object without using Include keyword
<p>So, I got an assignment that contain these file:</p>

<pre><code>animal.cpp // class that contain animal Object
human.cpp
</code></pre>

<p>Human object has animal object as its private instance. My question is how can I use declare animal object in human class? Usually there's a header file for animal object, so all I have to do is include the animal.h in human.cpp</p>

<p>However, in this case, my instructor forbid me to declare animal.h what should I do?</p>
