Delphi记录record中的变体

program Day4;

{$APPTYPE CONSOLE}

uses

  SysUtils,

  Util in 'Util.pas';

type

    TPerson = packed record

        ID : integer;

        case IsFullJob : Boolean of

            true: (

                Year : Cardinal;

            );

            false:(

                Hour : word;

            );

    end;

var

    s : string;

    ss : ShortString;

    p : TPerson;

begin

    Writeln('sizeof integer:',sizeof(integer));

    Writeln('sizeof cardinal:',sizeof(cardinal));

    Writeln('sizeof word:',sizeof(word));

    Writeln('sizeof boolean:',sizeof(boolean));

    Writeln('sizeof TPERSON:',sizeof(Tperson));

    p.ID := 110;

    p.Year := $80000001;      //$8 = 1000 b

    Writeln('p.year:',p.year);

    Writeln('p.hour:',p.hour);

    p.IsFullJob := true;

    Writeln('p.IsFullJob:',p.IsFullJob);

    readln;

end.

类似Ｃ中的联合体union．