The C/C++ Preprocessor Reference explains the preprocessor as it is implemented in Microsoft C/C++. The preprocessor performs preliminary operations on C and C++ files before they are passed to the compiler. You can use the preprocessor to conditionally compile code, insert files, specify compile-time error messages, and apply machine-specific rules to sections of code.

Preprocessor Directives
Describes directives, typically used to make source programs easy to change and easy to compile in different execution environments.

Preprocessor Operators
Discusses the four preprocessor-specific operators used in the context of the #define directive.

Predefined Macros
Discusses predefined macros as specified by ANSI and Microsoft C++.

Pragmas
Discusses pragmas, which offer a way for each compiler to offer machine- and operating system-specific features while retaining overall compatibility with the C and C++ languages.

C++ Language Reference
Provides reference material for the Microsoft implementation of the C++ language.

C Language Reference
Provides reference material for the Microsoft implementation of the C language.

Building a C/C++ Program
Provides links to topics discussing compiler and linker options.

Visual C++ Libraries
Provides links to the various libraries provided with Visual C++, including ATL, MFC, OLE DB, the C run-time library, and the C++ Standard Library.

Creating and Managing Visual C++ Projects
Describes the user interface in Visual Studio that enables you to specify the directories that the project system will search to locate files for your C++ project.