longs in managed C++

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songie D - 11 May 2004 11:56 GMT

Is a long in managed c++ a 64-bit number like in C#
If so how can I distinguish between that and one that's in some unmanaged code, and therefore that is 32-bit
Call it an int

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Ronald Laeremans [MSFT] - 11 May 2004 23:24 GMT

No, it is 32 bits.

Ronald Laeremans
Visual C++ team

> Is a long in managed c++ a 64-bit number like in C#?
> If so how can I distinguish between that and one that's in some unmanaged
> code, and therefore that is 32-bit?
> Call it an int?

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songie D - 12 May 2004 20:38 GMT

OK, being from MSFT maybe you'll know the answer to this.
What is the reason that a long in C# is 64-bits, while a long in
MC++ is 32-bits. Is it perhaps because it is predicted that C# is
the language of the future, while MC++ is there only to provide
IJW for those that feel the need to use it (for whatever reason),
and that we'll all be moving on to 64-bit processors soon anyway
so it makes sense to use a 64-bit variable?

> No, it is 32 bits.
>
[quoted text clipped - 5 lines]
> > code, and therefore that is 32-bit?
> > Call it an int?

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Doug Harrison [MVP] - 12 May 2004 21:45 GMT

>OK, being from MSFT maybe you'll know the answer to this.
>What is the reason that a long in C# is 64-bits, while a long in
[quoted text clipped - 3 lines]
>and that we'll all be moving on to 64-bit processors soon anyway
>so it makes sense to use a 64-bit variable?

I wouldn't presume to answer for Ronald, but my understanding is that
consideration of Win32/Win64 and other compatibility issues dictated int and
long remain 32 bits for the C++ compiler. It would be bad for Managed C++ to
define a larger size, because then you would throw IJW out the window. C#,
being a brand new language, had none of these concerns, but note that its
int type remains 32 bits, which is enough for most purposes. As in C++, your
primary integer data type in C# is int.

As for the future of C++ on .NET, not only is C++ not being back-burnered,
it's going to be much, much better in the next release. See this MSDN
article for more:

Write Faster Code with the Modern Language Features of Visual C++ 2005
http://msdn.microsoft.com/msdnmag/issues/04/05/VisualC2005/default.aspx

In some ways, such as the new support for deterministic finalization, it
will become superior to C#, and even viewed solely as a pure .NET language,
VC++ 2005 is looking very attractive.

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Doug Harrison
Microsoft MVP - Visual C++

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Tomas Restrepo \(MVP\) - 12 May 2004 03:44 GMT

Songie,

> Is a long in managed c++ a 64-bit number like in C#?
> If so how can I distinguish between that and one that's in some unmanaged code, and therefore that is 32-bit?
> Call it an int?

What Ronald said. Notice you can use __int64 (both in managed and unmanaged
code) to handle 64-bit numbers (or System::Int64 for just managed code)

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Tomas Restrepo
tomasr@mvps.org

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Ronald Laeremans [MSFT] - 12 May 2004 22:02 GMT

And you can also use the somewhat more portable "long long".

Ronald

> Songie,
>> Is a long in managed c++ a 64-bit number like in C#?
[quoted text clipped - 5 lines]
> unmanaged
> code) to handle 64-bit numbers (or System::Int64 for just managed code)

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Tomas Restrepo \(MVP\) - 13 May 2004 00:49 GMT

Hi Ronald,

> And you can also use the somewhat more portable "long long".

Ahh true! I had forgotten it is now supported! :)

thanks!

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Tomas Restrepo
tomasr@mvps.org

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longs in managed C++

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