&quot;int&quot; doesn&#x27;t reveal the intention of the programmer - they might just have used it because it&#x27;s &quot;int&quot;, not because it changes size based on what system you are targeting.<p>If they used &#x27;int_fast16_t&#x27; from &lt;stdint.h&gt;, you have at least an idea that they considered that it might only be 16 bits, and that it can be a larger type on systems where operations on 64-bit types are faster.