/Wp64 (Detect 64-Bit Portability Issues)
Detects 64-bit portability problems on types that are also marked with the __w64 keyword.
The /Wp64 compiler option and __w64 keyword are deprecated and will be removed in a future version of the compiler. If you use the /Wp64 compiler option on the command line, the compiler issues Command-Line Warning D9035. Instead of using this option and keyword to detect 64-bit portability issues, use a Visual C++ compiler that targets a 64-bit platform. For more information, see 64-Bit Programming with Visual C++.
By default, the /Wp64 compiler option is off in the Visual C++ 32-bit compiler and on in the Visual C++ 64-bit compiler.
Variables of the following types are tested on a 32-bit operating system as if they were being used on a 64-bit operating system:
If you regularly compile your application with a 64-bit compiler, you may want to disable /Wp64 in your 32-bit compilations, as the 64-bit compiler will detect all issues. For more information about targeting a Windows 64-bit operating system, see 64-Bit Programming with Visual C++.
To set this compiler option in the Visual Studio development environment
Open the project's Property Pages dialog box. For details, see How to: Open Project Property Pages.
Click the C/C++ folder.
Click the General property page.
Modify the Detect 64-bit Portability Issues property.