title: warning: expression result unused
body: <pre><code>char change(const char c){
    (c &gt;= 'A')&amp;&amp;(c &lt;= 'M') ? (c+'N'-'A') : 
  ((c &gt;= 'N')&amp;&amp;(c &lt;= 'Z') ? (c-('N'-'A')) : 
  ((c &gt;='a')&amp;&amp;(c &lt;= 'm') ? (c+'n'-'a') :
  ((c &gt;= 'n')&amp;&amp;(c &lt;= 'z') ? (c-('n'-'a')) : c )));
  }
  </code></pre>
  
  <p>Why I get "warning: expression result unused" and "error: control reaches end of non-void function [-Werror,-Wreturn-type]"?</p>