size of record

[JdeHaan]

Hi,

I have this record defined:

Code: Pascal  [Select][+][-]

1.   TBitData = packed record
2.     case Byte of
3.       0: (Bits64: UInt64);
4.       1: (Bits32: array[0..1] of UInt32);
5.       2: (Num: Double);
6.   end;
7.  

My question is, what is the exact size? Is it 64 bits or do I have to add 1 byte for the 'case Byte of'.
If the latter, how can I get a record with exactly 64 bits?

[BrunoK]

Code: Pascal  [Select][+][-]

1. program Project1;
2.  
3. type
4.   TBitData = packed record
5.     case byte of
6.       0: (Bits64: uint64);
7.       1: (Bits32: array[0..1] of uint32);
8.       2: (Num: double);
9.   end;
10. begin
11.   WriteLn(SizeOf(TBitData));
12.   ReadLn;
13. end.            

8

[marcov]

64-bit. The extra byte for the selector comes when you name the switch variable instead of just using the type, like:

Code: Pascal  [Select][+][-]

1.       TBitData = packed record
2.         case selector : Byte of
3.           0: (Bits64: UInt64);
4.           1: (Bits32: array[0..1] of UInt32);
5.           2: (Num: Double);
6.       end;
7.  

     

[JdeHaan]

Thanks