What is "stdarg.h"

stdarg.h is a header in the C standard library of the C programming language that allows functions to accept an indefinite number of arguments. It provides facilities for stepping through a list of function arguments of unknown number and type. C++ provides this functionality in the header cstdarg.

The contents of stdarg.h are typically used in variadic functions, though they may be used in other functions (for example, [[vprintf]]) called by variadic functions.