va_list

This is a type suitable for holding information needed by the three macros va_start(), va_arg() and va_end().

This macro initializes ap variable to be used with the va_arg and va_end macros. The last_arg is the last known fixed argument being passed to the function i.e. the argument before the ellipsis.

This macro retrieves the next argument in the parameter list of the function with type type.

This macro allows a function with variable arguments which used the va_start macro to return. If va_end is not called before returning from the function, the result is undefined.