CharInSet doesn't work with non English letters?

Question

I have updated an application from Delphi 2007 to Delphi 2010, everything went fine, except one statement that compiled fine but not working which is:

If Edit1.T         


        

Answer 1

This happens because set of char structured type (limited to 256 elements maximum) doesn't support Unicode at all. That is, any characters Ord(ch) > High(AnsiChar) being truncated in the set constructor and warning W1061 about narrowing WideChar to AnsiChar is being emitted. Look at the following testcase:

  { naturally, fails, emits CharInSet() suggestion }
  Result := 'س' in ['S','س'];

  { fails because second argument is set of AnsiChar }
  Result := CharInSet(
    'س',
    ['S','س']
  );

  { workaround for WideChar in AnsiCharSet, fails }
  Result := WideStrUtils.InOpSet(
    'س',
    ['S','س']
  );

  { a syntactical workaround, which finally works }
  Result := WideStrUtils.InOpArray(
    'س',
    ['S','س']
  );

  if Result then
    ShowMessage('PASS')
  else
    ShowMessage('FAIL');