ptr32-ptr64.md

description	title	ms.date	f1_keywords	helpviewer_keywords	ms.assetid
Learn more about: __ptr32, __ptr64	__ptr32, __ptr64	10/09/2018	__ptr32_cpp __ptr64_cpp __ptr32 __ptr64 _ptr32 _ptr64	__ptr64 keyword [C++] _ptr32 keyword [C++] ptr32 keyword [C++] ptr64 keyword [C++] _ptr64 keyword [C++] __ptr32 keyword [C++]	afb563d8-7458-4fe7-9c30-bd4b5385a59f

__ptr32, __ptr64

Microsoft Specific

__ptr32 represents a native pointer on a 32-bit system, while __ptr64 represents a native pointer on a 64-bit system.

The following example shows how to declare each of these pointer types:

int * __ptr32 p32;
int * __ptr64 p64;

On a 32-bit system, a pointer declared with __ptr64 is truncated to a 32-bit pointer. On a 64-bit system, a pointer declared with __ptr32 is coerced to a 64-bit pointer.

Note

You cannot use __ptr32 or __ptr64 when compiling with /clr:pure. Otherwise, Compiler Error C2472 will be generated. The /clr:pure and /clr:safe compiler options are deprecated in Visual Studio 2015 and unsupported in Visual Studio 2017.

For compatibility with previous versions, _ptr32 and _ptr64 are synonyms for __ptr32 and __ptr64 unless compiler option /Za (Disable language extensions) is specified.

Example

The following example shows how to declare and allocate pointers with the __ptr32 and __ptr64 keywords.

#include <cstdlib>
#include <iostream>

int main()
{
    using namespace std;

    int * __ptr32 p32;
    int * __ptr64 p64;

    p32 = (int * __ptr32)malloc(4);
    *p32 = 32;
    cout << *p32 << endl;

    p64 = (int * __ptr64)malloc(4);
    *p64 = 64;
    cout << *p64 << endl;
}

32
64

END Microsoft Specific

See also

Built-in types