7.15.1.2 The va_copy macro
Synopsis
#include <stdarg.h>
void va_copy(va_list dest, va_list src);
Description
The va_copy macro initializes dest as a copy of src, as if the va_start macro had been applied to dest followed by the same sequence of uses of the va_arg macro as had previously been used to reach the present state of src. Neither the va_copy nor va_start macro shall be invoked to reinitialize dest without an intervening invocation of the va_end macro for the same dest.
Returns
The va_copy macro returns no value.