CODEWITHSUNDEEP
c++types32bit-64bit
Azher Iqbal
Azher Iqbal

Reputation: 547

What is Compatible "int" type in both 32Bit & 64Bit windows in C++?

What is the compatible "int" datatype in C++ that can resize itself to 4 bytes on 32bit & 8 bytes on 64bit windows?

Although INT_PTR works fine but it reduces the readability as well as its description tells us to use it for pointer arithmetic.

Thanks

Upvotes: 6

Views: 751

Answers (5)

GManNickG
GManNickG

Reputation: 504313

The standard does not mention specific size requirements, only that each integral type must provide at least as much storage as the type before it. So int must hold as much as a short, and so on. You're better off specifying what you need them for.

If you're looking for integers that do not change size based on the operating environment, take a look at the Boost Integer Library, or the C99/C++11 header <cstdint>. This contains types such as uint32_t/int32_t and uintmax_t/intmax_t.

Most importantly, based off your question, it has: uintptr_t/intptr_t. These are guaranteed to have the correct size to hold a pointer on your platform.

Upvotes: 3

Goz
Goz

Reputation: 62333

under Visual Studio you are also offered __int3264 which does much the same as INT_PTR ...

Upvotes: 3

Tobias Langner
Tobias Langner

Reputation: 10828

This might help you: http://lists.debian.org/debian-user/2006/04/msg00681.html. Unfortunatly your question seems to be compiler dependant.

Upvotes: 0

Philippe Leybaert
Philippe Leybaert

Reputation: 171914

It really depends on the compiler. I think the only (more or less) reliable way is by using a pointer type like (void *).

I think the best way is by using some conditional processing in your header file and set a custom type:

#ifdef _WIN64
  typedef __int64 NATIVEINT;
#else
  typedef __int32 NATIVEINT;
#endif

(this sample is for Visual C++)

Upvotes: 1

avakar
avakar

Reputation: 32685

If you're looking for something standard, you're out of luck. The standard does not specify the size of any of the built-in datatypes.

Note, that INT_PTR does not imply pointer arithmetic. I means that the type will have the same size as void *, which is exactly what you want. It won't work on all platforms though (I'm pretty sure it's Windows specific).

Upvotes: 3

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