This video tutorial introduces the hash define preprocessor directive, explaining its use for creating symbolic constants and macros. It covers examples of symbolic constants, such as debug build, and macros that require arguments. The tutorial emphasizes the importance of naming conventions, using all capital letters for macros and constants. An example of a macro to find the maximum of two values is provided, illustrating text substitution before compilation. The video concludes with a preview of using hash define in Visual Studio, highlighting potential pitfalls and best practices.

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