title: Using CharInSet in Delphi or Firemonkey
body: <p>How do I use <code>CharInSet()</code> to get rid of this warning?</p>
  
  <pre><code>lastop:=c;
  {OK - if op is * or / and prev op was + or -, put the whole thing in parens}
  If (c in ['*','/']) and (NextToLastOp in ['+','-']) then
    Result.text:='('+Result.text+')';
  Result.text:=Result.text+c;
  </code></pre>
  
  <blockquote>
    <p>[dcc32 Warning] U_Calc1.pas(114): W1050 WideChar reduced to byte char in set expressions.  Consider using 'CharInSet' function in 'SysUtils' unit.</p>
  </blockquote>