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C++ Language/Preprocessing/Macros
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A "preprocessor macro" enables the effect of cut-and-paste of source code, from that macro's definition (in a #define statement) to anywhere the programmer "expands" that macro.
This cutting-and-pasting action could be parameterized.
If a macro has been defined to accept a parameter, its expansion is allowed to pass nothingness.
A "variadic macro" is written to accept a variable number of macro-parameters.
Additional information about macros (includes interactive examples)