Records are aligned unless you specify the "packed" attribute (ie TSample = packed record). The size returned by SizeOf *is* the real size for the record, that's the number of bytes used to hold the structure in memory.
Remember, you're not supposed to use non-packed records for anything outside your version of the Exe (no file-saving, no network transmission), and that's because alignment might be different for different compilers (or different versions of the same compiler). -- Cosmin Prund -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of CubicDesign Sent: Wednesday, May 16, 2007 6:20 PM To: [email protected] Subject: problems with SizeOf Hi. Can anybody tell me what should return this function Sizeof(TSample)? TSample = record SampleA: Smallint; SampleB: Smallint; SampleC: Smallint; SampleD: Smallint; BasePos: Integer; Base : char; QV : BYTE; Gray : Boolean; end; {Size= 2+2+2+2+ 4+ 1+ 1+ 1} Why it returns 16 instead of 15? It is because the data is aligned to word or double-word boundaries for faster access? How do I get the real size then? I want to save a matrix called CromaMX (CromaMX = array of TSample ) to disk using BlockWrite. How do I save it, without wasting disk space, because it looks that if I use: SizeChroma= Length(CromaMX)* sizeof(TSample); BlockWrite(F, CromaMX[0], SizeChroma); I will allocate too much space. _______________________________________________ Delphi mailing list -> [email protected] http://www.elists.org/mailman/listinfo/delphi _______________________________________________ Delphi mailing list -> [email protected] http://www.elists.org/mailman/listinfo/delphi
