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#include "c23-fallback.h"
#include <stdarg.h>
#include <stdio.h>
//#include <stdlib.h>
/**
** @brief A small, useless function to show how variadic
** functions work
**/
double sumIt(size_t n, ...) {
double ret = 0.0;
va_list va;
va_start(va);
for (size_t i = 0; i < n; ++i)
ret += va_arg(va, double);
va_end(va);
return ret;
}
/**
** @brief A simple debug stream
**
** Per convention no output is produced when this is null.
**
** This can be set local to the current thread, such that threads may
** print their debug messages to different files or streams.
**/
thread_local FILE* iodebug = nullptr;
/**
** @brief Prints to the debug stream @c iodebug
**/
[[gnu::format(printf, 1, 2)]]
int printf_debug(const char *format, ...) {
int ret = 0;
if (iodebug) {
va_list va;
va_start(va);
ret = vfprintf(iodebug, format, va);
va_end(va);
}
return ret;
}
int main(int argc, char* argv[argc+1]) {
if (argc < 4) return EXIT_FAILURE;
iodebug = stderr;
printf_debug("%g\n", sumIt(3, strtod(argv[1], nullptr), strtod(argv[2], nullptr), strtod(argv[3], nullptr)));
return EXIT_SUCCESS;
}
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