System.TFileRec

 TFileRec = packed record (* must match the size the compiler generates: 592 bytes (616 bytes for x64) *)
 Handle: NativeInt;
 Mode: Word;
 Flags: Word;
 case Byte of
 0: (RecSize: Cardinal); // files of record
 1: (BufSize: Cardinal; // text files
 BufPos: Cardinal;
 BufEnd: Cardinal;
 BufPtr: _PAnsiChr;
 OpenFunc: Pointer;
 InOutFunc: Pointer;
 FlushFunc: Pointer;
 CloseFunc: Pointer;
 UserData: array[1..32] of Byte;
 Name: array[0..259] of WideChar;
 );
 end;

struct DECLSPEC_DRECORD TFileRec
{
public:
 NativeInt Handle;
 Word Mode;
 Word Flags;
public:
 union
 {
 struct
 {
 unsigned BufSize;
 unsigned BufPos;
 unsigned BufEnd;
 char *BufPtr;
 void *OpenFunc;
 void *InOutFunc;
 void *FlushFunc;
 void *CloseFunc;
 System::StaticArray<Byte, 32> UserData;
 System::StaticArray<WideChar, 260> Name;
 };
 struct
 {
 unsigned RecSize;
 };
 };
};