DragonFlyBSD

#include <stdio.h>

#include <string.h>

#include <wchar.h>

int main(int argc, char *argv[])

{

  char out[64];

  wchar_t *in = L"Hello! \x20AC Hello!";

  const wchar_t *inptr = in;

  mbstate_t state = {0};

  size_t len = wcsrtombs(out, &inptr, sizeof(out), &state);

  printf("inptr - in: %d \n", inptr - in);

}