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Faster Builds and Smaller Header Files
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To speed the build process, Visual C++ provides the following defines that reduce the size of the Win32 header files.
VC_EXTRALEAN
WIN32_LEAN_AND_MEAN
Newly generated Visual C++ AppWizard applications automatically benefit from VC_EXTRALEAN. You can also manually define VC_EXTRALEAN to speed the build process of many legacy MFC applications.
Non-MFC C++ and C applications can define WIN32_LEAN_AND_MEAN and any applicable NOservice defines, such as NOSOUND (see ProgramFiles\Microsoft Visual Studio\VC98\include\Windows.h and ProgramFiles\Microsoft Visual Studio\VC98\MFC\Include\afxv_w32.h), to reduce their build times.
To add these defines, from the Project menu, choose Settings. The Projects settings dialog box appears. Click the C/C++ tab. In the Category list, select Preprocessor. Add the desired definitions to the Preprocessor Definitions box.
Knowledge Base article Q151666 also discusses these preprocessor definitions