sure ok.
On Thu, 25 Aug 2011 11:57:26 +1200, Robo wrote: I think your TLogData contains storage for an integer (TLogType, 4 bytes), and a pointer to an array (4 bytes). However, what you need is enough memory to store the entire array, not just the pointer, so you should get the size of the array to get the correct size. On Thu, Aug 25, 2011 at 11:40 AM, David Moorhouse (DUG) wrote: I have the following code snippet type PConstArray = ^TConstArray; TConstArray = array of TVarRec; function CreateConstArray(const Elements: array of const): TConstArray; type TLogType = (ltError, ltWarn, ltInfo); PLogData = ^TLogData; TLogData = record LogType: TLogType; LogArgs: TConstArray; end; .... procedure TUserClass.Log(const LogType: TLogType; const Args: array of const ); var LogData: PLogData; begin // size of record TLogData does not work GetMem(LogData, sizeof(TLogData)); LogData.LogType := LogType; // blows up on next line LogData.LogArgs := CreateConstArray(Args); // ... do some other stuff with the LogData item finally calling FreeMem end; function CreateConstArray(const Elements: array of const): TConstArray; var I: Integer; begin SetLength(Result, Length(Elements)); for I := Low(Elements) to High(Elements) do Result[I] := // assign a TVarRec here end; The code that assigns the memory only assigns 8 bytes - and an access violation ensues. If I replace the call to "sizeof" with the number 16, the code works fine. My understanding of dynamic arrays was that the compiler created a 4 byte field before the first element that contained the length of the array. So why does the sizeof function not reflect this ? And why do I need 16 bytes not 12 (4 for LogType + 4 for length of array + 4 for array pointer)? Also regardless of the number of items in the open array parameter, 16 bytes works, so it does not relate the length of the TConstArray. Your thoughts ? David _______________________________________________ NZ Borland Developers Group - Delphi mailing list Post: delphi@delphi.org.nz [2] Admin: http://delphi.org.nz/mailman/listinfo/delphi [3] Unsubscribe: send an email to delphi-requ...@delphi.org.nz [4] with Subject: unsubscribe Links: ------ [1] mailto:del...@moorhouse.net.nz [2] mailto:delphi@delphi.org.nz [3] http://delphi.org.nz/mailman/listinfo/delphi [4] mailto:delphi-requ...@delphi.org.nz
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