Delphi中GUID相等检查中经典指针应用

type
  PGUID = ^TGUID;
  TGUID = packed record
    D1: LongWord;
    D2: Word;
    D3: Word;
    D4: array[0..7] of Byte;
    class operator Equal(const Left, Right: TGUID): Boolean;
    class operator NotEqual(const Left, Right: TGUID): Boolean;
    class function Empty: TGUID; static;
  end;
 
 IntegerArray  = array[0..$effffff] of Integer;
  PIntegerArray = ^IntegerArray;

function IsEqualGUID(const Guid1, Guid2: TGUID): Boolean;
var
  a, b: PIntegerArray;
begin
  a := PIntegerArray(@Guid1);
  b := PIntegerArray(@Guid2);
  Result := (a^[0] = b^[0]) and (a^[1] = b^[1]) and (a^[2] = b^[2]) and (a^[3] = b^[3]);
end;