Sort TStrings (TMemo.Lines) in Lazarus-IDE

sort-tstrings.pas

procedure SortStrings(strs: TStrings);
var
  sl: TStringList;
begin
  sl := TStringList.Create;
  sl.Text := strs.Text;
  sl.Sort;
  strs.Text := sl.Text;
  sl.Free;
end;

zzz-irc.txt

Freenode IRC #lazarus-ide 2016-11-11
<Sven_vB> hi :)
<Sven_vB> what's the easiest way to sort the lines in my TMemo? I think I've
  used Memo.Lines.Sort or Memo.Sorted := True back in the days but it seems
  to not work nowadays.
<Sven_vB> oh I see, I have to remind the lines that they're TStringList
<Sven_vB> nope, that makes an "Invalid type cast."
<Sven_vB> there's "TStrings.Sorted" in the "See also" section of
  http://lazarus-ccr.sourceforge.net/docs/rtl/classes/tstringlist.html ,
  but when I follow the link, Firefox can't find any occurrence of "sort"
  in the target page. :-/
<Sven_vB> that TypeCast won't even work when I replace the Lines with a real
  TStringList?? EdtVars.Lines.Free; EdtVars.Lines := TStringList.Create;
  (EdtVars.Lines as TStringList).Sort;
<Sven_vB> seems I have to make my own helper proc where I copy the .Text into
  a temporary TStringList, sort it, and copy it back. :-( cumbersome but works.