TRectD = record
Left : double;
Top : double;
Right : double;
Bottom : double;
function IsEmpty : Boolean;
//Normalize: Returns True if either Top & Bottom or Left & Right are swappped
function Normalize : Boolean;
function Width : double;
function Height : double;

For Delphi compilers that don't support record methods (ie compilers prior to D2006), this structure is defined instead as an old style object instead of a record.