title: What are common approaches to meaningful function return values?
body: <p>I know <code>EXIT_SUCCESS</code>/<code>EXIT_FAILURE</code> is typically used for main() exit to indicate the successfulness of a program.</p>
  
  <p>But is it also used (commonly or suggested) for normal function returns? I'm trying to write some "standard" code so wondering if I should use them instead of 0 or -1..</p>