title: kbhit() on MacOS to detect keypress
body: <p>I am new to C++ on MacOS.
  I got an error when I used <code>kbhit()</code> in my program.</p>
  <p>I used <code>#include&lt;conio.h&gt;</code> but got error too, so I searched and test with <code>#include&lt;curses.h&gt;</code> but error is still remained.</p>