personRec.ID  := 111;
  personRec.tag := False;
  personRec.B   := 100;    {工人的日薪}
end;

//最经典的变体结构莫过于 Delphi 定义的 TMessage 结构了, 两组数据分分合合都是一体, 多么巧妙啊!

TMessage = packed record
    Msg: Cardinal;
    case Integer of
      0: (
        WParam: Longint;
        LParam: Longint;
        Result: Longint);
      1: (
        WParamLo: Word;
        WParamHi: Word;
        LParamLo: Word;
        LParamHi: Word;
        ResultLo: Word;
        ResultHi: Word);
  end;