C / C++ / MFC

4-Mar-04 5:38

Hi,

I just upgraded a portion of my code from int to __int64, everything looked fine but the only problem is that it looks like this data type could not be serialized.....

Anyone know a 64bit data type in MFC that can be serialized ?

Shay\
error C2593: 'operator <<' is ambiguous
error C2679: binary '>>' : no operator defined which takes a right-hand operand of type '__int64' (or there is no acceptable conversion)

basementman4-Mar-04 5:45

4-Mar-04 5:45

It is not one of the supported data types that the CArchive class has provided overloaded operators for. So, you will need to use CArchive Write and Read methods, passing the address of the __int64 var.

onwards and upwards...

Shay Harel4-Mar-04 6:18

4-Mar-04 6:18

Thanks, but one more thing

When I use ar.Write or ar.Read, it looks for a pointer to a buffer.
It looks like when I read, it read more that needed, even though I specified 64 in the second paramter.

So....
If I need to serialize a 64 bit number using write, should it be:
ar.Write (&number,64)?
and read back:
ar.Read (&number,64);

basementman4-Mar-04 6:39

4-Mar-04 6:39

first off, your __int64 variable is NOT 64 bytes long. It is 64 BITS long, which, when divided by 8 bits per byte, is 8 bytes. So, you should pass 8 for the second param ( or sizeof(__int64) ).

ar.Write(&number,8);
-- or --
ar.Write(&number,sizeof(__int64));

onwards and upwards...

Shay Harel4-Mar-04 6:42

4-Mar-04 6:42

dooooooooooouuuuuuuuuuughhhhhhhhhhh !!!!!!!!!

Thanks for pointing my stupidity, that's an excellent proof for why you should not skip lunch.

Shay

BlackDice4-Mar-04 5:57

BlackDice

4-Mar-04 5:57

Try using the LARGE_INTEGER data type. Text between asterisks is text quoted directly from the MSDN documentation on the data type

***********************
LARGE_INTEGER

The LARGE_INTEGER structure is used to represent a 64-bit signed integer value.

Note Your C compiler may support 64-bit integers natively. For example, Microsoft® Visual C++® supports the __int64 sized integer type. For more information, see the documentation included with your C compiler.

typedef union union
{ struct
{ DWORD LowPart;
LONG HighPart;
}; LONGLONG QuadPart;
} LARGE_INTEGER, *PLARGE_INTEGER;
*************************************

hope this helped!

If it's broken, I probably did it

bdiamond

Steve S4-Mar-04 6:49

Steve S

4-Mar-04 6:49

Darn. Beat me to it. I was going to suggest doing something similar and then using the standard CArchive operators on the smaller bits.

Steve S

BlackDice4-Mar-04 8:47

BlackDice

4-Mar-04 8:47

well I'm glad to see I beat somebody to something for once Cool | :cool:

If it's broken, I probably did it

bdiamond

Mike Dimmick4-Mar-04 6:08

Mike Dimmick

4-Mar-04 6:08

Write your own operator<< and operator>> functions.

Stability. What an interesting concept. -- Chris Maunder

David Crow4-Mar-04 7:13

David Crow

4-Mar-04 7:13

I once wrote an extension to the CArchive class that handled serialization of the __int64 type. I can send it to you if you'd like.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Shay Harel4-Mar-04 7:37

4-Mar-04 7:37

First of all, you can send it, it never hurts to share someone elses wisdom.
Second, I already utilized the Write/Read functions of the archive.

Thanks!

jbarton4-Mar-04 10:00

jbarton

4-Mar-04 10:00

I prefer to write a global operator>> and operator<< for datatypes like this, so that I can still use the syntax of a stream operator with the archive.

<br />
CArchive& operator<<( CArchive& archive, __int64 value )<br />
   {<br />
   archive.Write( &value, sizeof(__int64) );<br />
   return archive;<br />
   }<br />
<br />
CArchive& operator>>( CArchive& archive, __int64 value )<br />
   {<br />
   archive.Read( &value, sizeof(__int64) );<br />
   return archive;<br />
   }<br />

This works for simple data types. I use this for bool as VC6.0 doesn't implement serialization for bool, but this should also work fine for __int64.

Best regards,
John

khb5-Jul-09 10:13

khb

5-Jul-09 10:13

Thanks for the tip! But don't forget to pass in the second parameter of operator>> by reference (__int64& value). Then it works perfectly!

Regards
Marcus

basementman4-Mar-04 9:35

4-Mar-04 9:35

I finally beat you to an answer.... you're slacking off!!;P

onwards and upwards...

Custom Build for Empty Project?

David Crow4-Mar-04 9:46

David Crow

4-Mar-04 9:46

My apologies. I was working on an article that had me sidetracked.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Brian van der Beek4-Mar-04 5:19

Brian van der Beek

4-Mar-04 5:19

I have an empty Visual C++ 6.0 project that I use to build a bunch of projects (by setting them as dependant projects). But before I start building I want to update the build numbers in the resource files of these projects.
I created a little app. for this, but I can't seem to find a way to kick it off, because my empty project does not have a custum build step.
Anyone got a clue on how to do this?

Re: Custom Build for Empty Project?

basementman4-Mar-04 7:20